Tycoon baulks at fee for UK's costliest home

Lakshmi Mittal, the Indian steel tycoon and New Labour donor, faces High Court action over the purchase of Britain's most expensive house.

Mr Mittal, the fifth richest man in the country, lavished £30m on the wedding of his daughter in Paris last month and in April paid out a reported £70m for a 15-bedroom property next door to Kensington Palace in London.

Yet legal proceedings lodged last week accuse Mr Mittal and his wife of attempting to save money in a time-honoured fashion - by cutting out the middle man, or in this case, woman.

Adina Kohn, 52, a property consultant to the rich and famous, has issued High Court proceedings claiming she is owed a finder's fee of around £350,000 from the sale of the mansion, plus VAT, interest and damages.

She accuses the Mittals of going "behind her back" when they purchased 18-19 Kensington Palace Gardens from the Formula One millionaire, Bernie Ecclestone, who, like Mr Mittal, has been a Labour Party donor.

Comprising two former embassies, Russian and Egyptian, knocked together, its 55,000 square feet now include an underground car park, a swimming pool partially inlaid with precious stones, a ballroom and Turkish baths.

It is, though, well within the budget of Mr Mittal, 53, who owns the world's second-largest steel company, LNM, and is said to be worth £3,500m. His £125,000 donation to the Labour Party two years ago led to a "cash for favours" row when it emerged that Tony Blair had intervened to help his purchase of the Romanian state steel industry.

The London property is already at the centre of a legal dispute as another former owner, the Iranian art expert Professor David Khalili, is suing Bernie Ecclestone for a share of the proceeds of the sale. (Professor Khalili claims to have had a part share in the equity of the ownership.)

Ms Kohn owns ASK Property Consultants in Hampstead and describes herself as specialising in "the very top end of the market". A glamorous figure who drives a red Ferrari, she is one of only a handful of similar property "matchmakers" who rely on commission from searching out suitable homes for the rich and famous, taking a 0.5 per cent fee. Her clients are understood to have included Kate Winslet and her film director husband Sam Mendes

The skill of professionals such as Ms Kohn lies partly in locating desirable properties that are not on the market and then persuading the owners to sell. Footballers, actors and leading industrialists have all turned to the services of matchmakers when looking for homes. The sums involved are so huge that even a tiny percentage can produce six-figure fees. Ms Kohn herself lives in a Hampstead house that once belonged to the pop star Sting.

She was not available to speak last week, but friends say she is upset by the row, the first time in 30 years in which she has found herself in dispute over non-payment. In seven years of working with the Mittals she had become a friend of the family and was expecting to be among the 1,000 guests invited to last month's wedding of Vanisha Mittal to Amit Bhatia.

She first approached Lakshmi and Usha Mittal "cold" in 1997 and agreed to receive 0.5 per cent on the purchase of any property she introduced. She showed them the Kensington Palace Gardens house in 1997, arranged a viewing for the Mittals and their children, and made an offer of £45m on their behalf, which was rejected. Then in May 2003, the Mittals showed renewed interest and asked Ms Kohn to enquire again about the property before telling her they would not proceed after all.

In April this year, she was surprised to find the Mittals were reported to have completed the purchase. According to her lawyers, the sale went ahead despite the fact that only days previously she had shown them other properties in the same road.

Jonathan Goldberg, a well-known QC acting on behalf of Ms Kohn, said: "My client is confident she has a genuine case morally and legally and that she has done her job and is entitled to her money.

"My client is only worried that Mr and Mrs Mittal, having just spent £70m on buying their house and £30m on their daughter's wedding, are now having to scrimp and save on her commission to make ends meet."

Neither the Mittals nor their solicitors were available for comment yesterday. But it is understood they claim to have bought the property after the intervention of a new agent instructed by the seller, Mr Ecclestone. Ms Kohn, they say, was not the "cause" of the sale.