Lewis, of law firm Taylor Hampton and representing police detective Richard Horton, said Horton had filed for misuse of confidential information, breach of confidence and deceit at London's High Court this week.

The Times exposed Horton as the author of the blog, in which he wrote about police work under the name NightJack, in 2009. Horton had sought an injunction to protect his anonymity but lost his case.

Judge David Eady ruled that the unmasking of Horton was in the public interest.

The Times did not disclose at the time that it had obtained the information about Horton's identity through email hacking, and its reporter implied he had discovered it through publicly available information on the Internet.

Rupert Murdoch's British newspapers, part of his News Corp media empire, are at the centre of several criminal investigations for phone hacking, computer hacking and bribery.

The matter blew up into a national scandal last July when it emerged that the News of the World tabloid had hacked into the voicemails of missing schoolgirl Milly Dowler, who was later found murdered.

Lewis, who is also the Dowler family's lawyer, said Horton now contended he would have won his case had it been disclosed that the information was obtained through email hacking, for which there is no public interest defense.

"He would have got his injunction but for the false evidence, and he would have been anonymous," Lewis said.

Horton is seeking aggravated damages and exemplary damages. Lewis declined to estimate how large these might be, saying he was not aware of any legal precedent.

The editor of the Times, James Harding, apologized in February for the email hacking when he gave evidence to the Leveson Inquiry, a judge-led inquiry ordered by Prime Minister David Cameron at the height of the phone-hacking scandal.

The Times reporter, Patrick Foster, has left the newspaper.

Rupert Murdoch and his son James are also expected to be called as witnesses to the Leveson Inquiry later this month.

News International, News Corp's British newspaper arm, confirmed that the claim had been filed and declined to make any further comment.

(Reporting by Georgina Prodhan; Editing by Andrew Callus)

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