Property: There's a prostitute living in my house: Joanna Vickers and her husband thought that using a firm of estate agents to let their London home would avoid problems. Then they received a telephone call . . .

OUR Peter Mayle-style getaway in southern France was interrupted early one morning by a phone call from our neighbour in London. 'I thought you'd like to know,' she said, 'that the tenant in your flat is a prostitute, and that the foreman of the building site across the road is living there, too. Every morning there's a queue of builders on the doorstep. She has 10 or 12 men up there every night and I've seen them rushing through the entrance hall half-naked.'

Our worst fears had been confirmed. All our friends had horror stories about letting their homes, and had advised against it. To reduce the risks, we had employed a firm of estate agents (at vast expense) to find and vet the tenant and tie up all legal loopholes. At least we knew that every precaution had been taken; or so we thought.

We immediately sent off a letter to the agents about this development, explaining that we would have to make a special trip back to England to sort out the problem. On our return, the agents suggested that a polite note to the tenant, pointing out that the premises were not to be used for business purposes, might just do the trick.

At worst, they said, she would stop paying the rent and that would be to our advantage, because we would then have the legal right to expel her within 21 days and our problems would be over. This was the beginning of an alarming period in which our emotions see-sawed between despair and elation.

Two weeks later, still with no reply from our tenant or any contact from the agents, we telephoned to find out what was going on. It emerged that the promised letter of warning had never been sent, which accounted for the lack of response. No explanation or apology was offered, nor was any mention made of another matter which was by now beginning to niggle: we had never received, despite repeated requests, copies of the three written references the agents were supposed to have obtained before the tenant moved in. Once again, these were promised by next post.

Two minutes after we had put the phone down, who should ring but the tenant, who called herself Julie, although that was probably not her real name. She wanted to know if we would be willing to renew the tenancy for another six months because she liked the flat and was very happy there. My husband said he was not willing to do so because there had been complaints from neighbours of constant comings and goings during the night, which he was having to deal with. In aggrieved tones, Julie protested that all comings and goings were to do with the flat above, where the builders were living. She then went on to explain that she had been obliged to change the locks to the flat, as she had lost her keys. Taken aback, my husband meekly asked for a key to be sent to us. She agreed.

At this stage, we began to have doubts. Perhaps our neighbour had been mistaken. Perhaps an innocent young woman had been unjustly accused; perhaps she had every right to be indignant. She had, after all, paid the rent on time and, since that was the main aim of the exercise, maybe we should calm down and let sleeping dogs lie.

A week later, our doubts were further increased by Julie's reply to the agents' promised letter of warning. She claimed that she worked for a well-known West End night-club, doing its accounts, and rarely had visitors to the flat because she was tired after her work.

The builders, on the other hand, were using the upstairs flat as a tea-room, which explained all the comings and goings. The day after this letter arrived, she stopped paying the rent.

An enlightened law firm that we knew about offers a free legal advice clinic on Thursday afternoons, so we went along. We had been assured by the agents that we could get our tenant out within 21 days. Was this true? Well, no. How long would it take? About three months, the amount of time left for the tenancy to run. How much would it cost? That depended. As long as the tenancy agreement had been served correctly at the outset and there were no complications, it would be less than pounds 500.

The solicitor advised us to go and see the tenant, try to establish a friendly relationship and ask her for the money. This seemed sensible advice, so next morning we went to London.

By now we felt thoroughly disgruntled with the agents, who seemed to have done nothing to earn their fee except introduce us to a dodgy tenant and then leave us to sort out the mess. They had taken their pounds 650 fee for the six months' tenancy out of the first month's rent, so they were well covered. We arranged to see them in order to set out our grievances and establish what to do next.

During the meeting it became clear that, not only had they never received written references for our tenant (apart from a non-committal note from a firm of accountants in Essex), but also that they did not even have her telephone number - so they could not ring her to ask why the rent had not been paid. They admitted they were mistaken about the 21-day eviction, but gave us the telephone number of their solicitor, which turned out to be the most useful thing they did during the entire fiasco.

At the flat we got no reply, but a phone call to the agents' solictor put us in a more cheerful mood: he was confident, knowledgeable and quick-witted. He advised us to put a note under the door, asking why the rent had not been paid and telling the tenant she should phone us within 24 hours or we would be forced to take legal action.

The phone call came within an hour. 'I'm very sorry - why didn't you telephone me before? There can't be enough money in my current account at the moment. Yes, of course I'll give you a cheque straight away. No, I'm afraid it isn't convenient for you to come over now, but I'll give it to the lady downstairs in the morning.' The poor victimised woman - how could we have worked ourselves up into such a lather over nothing?

Next morning I collected the cheque. The amount in words did not tally with the amount in figures. We suspected this was a delaying tactic, and the bank clerk confirmed that the cheque would almost certainly be returned. Another phone call to the lawyer revealed that if the phrase 'Words and figures do not tally, please accept lower amount' was written on the cheque, the bank should honour it. But whatever happened, he said, this was good news, because we now had details of her bank account, and if it came to eviction orders the cheque was legal evidence of her refusal to pay.

To speed things up, we made an appointment to see our bank manager so as to pay in the cheque and explain the saga. A telephone call to the tenant's bank revealed that a stop had been put on the cheque (conclusive proof, we thought, of her guilt) but we were told it had to go through the banking system anyway, and that would take four days.

Despair reigned during the following weekend until, using a Visa card to withdraw money from the bank, we noticed that the account was again mysteriously in the black. The rent had been paid. The standing order had been reinstated, and the stopped cheque had been merely a measure on the tenant's part to prevent the rent being paid twice. The poor victimised woman.

The following day an alternative possibility occurred to us - and a phone call to the bank confirmed that the money had come from the stopped cheque, in error. But we were told that, because it was only 20 minutes short of the four working days since the cheque had been paid in, unless the tenant's bank realised its mistake in the next 20 minutes we would be legally entitled to the money. The bank did not.

Then came more good news, this time from the agents: our tenant had done a bunk, leaving the keys with them. They had, apparently, already shown some new prospective tenants around the flat, and these people wanted it. My husband jumped in the car and once again set off for London. He was surprised to see a sign in the agents' window advertising our flat - for pounds 150 a week, although the agreed rent had been pounds 200. Inside, a jubilant estate agent announced that he had succeeded in negotiating an extra pounds 5 a week.

My husband pointed out that this was pounds 45 too little, and confronted the agents with what was by now a blatantly obvious fact: that they had lost the file on our flat which contained the tenancy agreement, the tenant's scanty references and the documents we would have needed for legal proceedings. They did not deny it.

A check of the flat revealed it to be in surprisingly good condition, with only minor items missing. A mysterious hole had been cut into the back of a built-in wardrobe, four inches square, into a space which connects with the upstairs flat. To conceal a video camera? We will never know. The only other clues were receipts for expensive clothes bought in South Molton Street, and a mattress soaked with massage oil.

But the final irony was that the tenant had left a leaflet from an insurance company in a drawer. It gave details of a special policy for landlords offering cover for legal expenses.

Joanna Vickers is a pseudonym.