Law appeared as a witness at the trial of two former editors of Rupert Murdoch's now-defunct News of the World tabloid — Rebekah Brooks and Andy Coulson — and five others on charges related to illegal eavesdropping. The defendants deny all the charges.
The "Sherlock Holmes" star was for years a favourite of Britain's tabloid press, which reveled in details of his relationships with designer Sadie Frost and actress Sienna Miller.
Law said that his media profile rose after he was nominated for an Academy Award in 2001 for "The Talented Mr. Ripley." From then on, he said, "there seemed to be an unhealthy amount of information" about him in the press, and he would often arrive at places with his children to find photographers already there.
Law, Frost and Miller are among scores of celebrities, politicians and others who have been paid compensation for phone hacking by Murdoch's News Corp. Murdoch closed the News of the World in 2011 after details emerged of the scale of its snooping.
But a defence lawyer suggested Monday that some of the information in 2005 News of the World stories alleging an affair between Law's then-girlfriend Miller and actor Daniel Craig might have had another source — Law's associates.
"I didn't know anyone around me was talking to the newspapers," said the 41-year-old actor, who gave evidence for just over an hour at London's Central Criminal Court.
Coulson's lawyer, Timothy Langdale, asked Law if he knew that a member of his immediate family had been giving information to the News of the World in exchange for money.
"I was not aware of that," Law said. Asked when he first heard of the allegation, Law said: "Today."
Law was shown the name of the family member on a piece of paper. It was not shown to the jury or journalists.
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