Former Mirror journalist who admitted phone hacking says it has been rife at the company 'for many years'

Graham Johnson said the company had failed for four years to acknowledge the extent of phone hacking

Graham Johnson leaving court in London yesterday (PA)

The board of the company which owns the Daily Mirror and its sister newspaper titles was forced to deny that it is concealing the extent of its exposure to phone hacking claims during a stormy meeting with shareholders.

Senior executives at Trinity Mirror were accused by a former senior journalist on the Sunday Mirror, who has admitted phone hacking, of “not being straight” about the number of likely damages cases faced by the group, which has set aside £12m to deal with compensation claims for illegal eavesdropping.

Graham Johnson, the former investigations editor of the Sunday Mirror, told the company’s annual general meeting at a four-star hotel in London’s Docklands that he believed phone hacking had been rife at Mirror titles for “many, many years” and “hundreds” of potential claims were likely to arise from the illegal activity.

Mr Johnson, who voluntarily handed himself in to police in 2013 over phone hacking of a single individual arising from an investigation into a gangland figure and was sentenced to community service in January, said the company had failed for four years to acknowledge the extent of phone hacking.

He said: “You could have phoned me… and I could have told you that phone hacking was going on at the Mirror for many, many years… Now it is costing you millions of pounds in legal fees that you are having to pay out.”

Mirror Group Newspapers (MGN) earlier this year admitted hacking the phones of eight public figures, including BBC executive Alan Yentob and former footballer Paul Gascoigne, at a civil trial during which it was accused of undertaking “industrial scale” voicemail interception and being more prolific in using the technique than the News of the World.

Trinity Mirror last year increased the sum it has set aside to deal with phone hacking claims from £4m to £12m but critics argue its final bill from the scandal will be significantly higher. The total cost to Rupert Murdoch’s News Corp of the fallout from its illegal newsgathering techniques, including the cost of criminal trials, currently stands at about £310m.

But David Grigson, the chairman of Trinity Mirror, strongly denied Mr Johnson’s allegations, saying the company was dealing with an unspecified number of claims but it could not quantify how many more might follow and would not work on “speculation”.

Mr Grigson told shareholders: “I have heard this from a few people that there are hundreds of claims in the pipeline. There are claims that we have received. I can’t speculate about claims that we haven’t.”

He added: “There are potentially more claims. I completely agree with that. I don’t know [how many] because I can’t put myself in the mind of people whose phone may or may not have been hacked all those years ago and say whether they are going to make a claim or not. If they do, we’ll look into it. If they were, we’ll pay them compensation for that intrusion.”

In its trading update, Trinity Mirror said its underlying revenues had fallen by eight per cent in the first quarter of this year as the newspaper market continues to contract. But it said its income from digital media had grown by nearly 30 per cent year on year and it had net cash of £20m at the end of April compared with a net debt of £19m at the same time last year.