The Sun newspaper has apologised in the High Court for accessing private information on a stolen mobile phone belonging to a Labour MP.
Police told Siobhain McDonagh her text messages had been accessed after her phone was stolen in October 2010.
The Sun, which has not admitted the theft of the phone itself, is to pay the MP "very substantial" damages.
The court has heard "possibly hundreds" of new claimants are seeking damages from the now defunct News of the World.
The hearing is the latest in a series before Mr Justice Vos relating to civil damages claims brought by people from all walks of life over the phone-hacking scandal.
Former boxer Chris Eubank, who appeared at the same hearing, claimed News International, which owned News of the World (NoW) publisher News Group Newspapers, had "destroyed" his life and "made a mockery" of the British justice system.
He rejected a "derisory" offer of £21,000 in damages from News Group Newspapers, which also publishes The Sun, and alleged that its actions had led to the failure of his marriage.
Representing himself in court, Mr Eubank added he was confident that evidence relating to his case would get in the public domain shortly and he looked forward to the "gargantuan battle" ahead of him.
Ms McDonagh, who represents London constituency Mitcham and Morden and was a parliamentary private secretary to Labour's John Reid when he was Defence Secretary, had her phone stolen from her car in Colliers Wood, south-west London.
David Sherborne, representing Ms McDonagh, told Mr Justice Vos that in June 2012, officers from Operation Tuleta - Scotland Yard's investigation into privacy breaches including the alleged hacking of computer and mobile phones - had "obtained evidence" that the Sun had accessed her text messages from about October 2010.
Mr Sherborne said it appeared the newspaper had "accessed and/or acquired" the device.
The MP had previously obtained a court order requesting the phone be handed over with any relevant information, but the newspaper was unable to provide it.
Ms McDonagh told the BBC she was "not hung up on her own privacy" but said she "felt terrible on behalf of her friends".
She said: "They'd texted me personal stuff that wasn't for everybody's eyes," adding that because their numbers were in her phone, "I'd exposed those people to having their messages hacked."
The Sun's lawyer said the newspaper accepted that her mobile phone "should not have been accessed" and added: "There has been a serious misuse of her private information".
Dinah Rose QC told the judge: "Through me [The Sun] offer their unreserved apology to the claimant for what has happened.
"Furthermore they have undertaken to the court not to use any information so obtained nor to access or attempt to access by unlawful means the claimant's private information."
The judge heard that "potentially hundreds of victims" could seek damages from News Group following a new Metropolitan Police investigation.
Hugh Tomlinson QC told the hearing that the new claims could arise from Operation Pinetree, the Met Police probe into a second phone-hacking conspiracy at NoW.
It forms part of Operation Weeting, the Met's ongoing investigation into claims of phone hacking at the now defunct Sunday tabloid.
He added it was "not known at the moment how many more claims may be issued".
Some 145 victims have recently settled claims with News Group as civil cases continue to move through the court. Currently more than 20 cases are still waiting to be heard.