Mirror hit by High Court claims over phone hacking
Ex-England football manager Sven-Goran Eriksson is among four people taking legal action against Mirror Group Newspapers for alleged phone hacking.
The claims against the publisher of the Daily and Sunday Mirror and the People were filed at the High Court on Monday.
Mr Eriksson's claim relates to a time when Piers Morgan edited the Daily Mirror. Mr Morgan denies phone hacking.
Trinity Mirror, which owns Mirror Group, declined to comment. Meanwhile, shares in Trinity Mirror fell by 12.5%.
The three other claimants are Coronation Street actress Shobna Gulati, who plays Sunita Alahan; Abbie Gibson, a former nanny for the Beckham family; and Garry Flitcroft, the former captain of Blackburn Rovers football team.
However, a spokesman for the Mirror Group said it was "unaware" action had been taken at the High Court.
Until now, the UK phone-hacking scandal has centred on Rupert Murdoch's News International and its now closed News of the World newspaper.
This is the first legal action in the scandal against another newspaper group.
BBC legal correspondent Clive Coleman says if there is any substance to the claims then it would be a major development.
He says the claims are similar in type to those brought against News International.
So far, more than 200 people have brought civil claims against that company, with 155 currently before the High Court. About 60 have already been settled.
Our correspondent says that the claim from Mr Eriksson, who was England manager between 2000 and 2006 and later managed Manchester City and Leicester City, is said to relate to a time when Mr Morgan was the editor of the Daily Mirror. He was editor between 1995 and 2004.
Mr Morgan, who is now a chat show host for US broadcaster CNN, was questioned about phone hacking during his appearance at the Leveson Inquiry, the independent probe set up by the government into the phone-hacking scandal.
During his appearance, he repeated his denials of any knowledge or involvement in the illegal practice.
Our correspondent says civil cases have been absolutely critical to "cracking open the entire story" of phone hacking after the criminal justice system had "effectively shut down" when private investigator Glenn Mulcaire and ex-News of the World royal editor Clive Goodman were jailed for hacking in 2007.
The civil cases forced parties to disclose evidence that "blew away" News International's claim that the practice was down to one rogue reporter, resulting in the reopening of the Met Police investigation into hacking and later the initiation of the Leveson Inquiry.
Mark Lewis, solicitor for the claimants, told the BBC that he would not be revealing what level of financial compensation his clients were seeking.