British actor Jude Law has given evidence in the phone-hacking trial, telling the jury that the media seemed to have an "unhealthy amount of information" about his private life.

Mr Law is the most high-profile celebrity so far to give evidence at the trial, where several senior News of the World executives deny conspiring to illegally access voicemails between 2000 and 2006.

The 41-year-old said he had recently discovered that a member of his family had been in contact with the now-closed News of the World at the time he was featured in the tabloid.

However, he said he was surprised at suggestions from defence lawyers that this person was being paid.

He told the jury that he had been under intense media scrutiny between about 2001, following his nomination for an Oscar for "The Talented Mr Ripley", and 2005 or 2006, a period in which he dated actress Sienna Miller.

"There seemed to be an unhealthy amount of information that people, or someone, had that meant they had access to my life and my whereabouts," Mr Law said.

He told London's Old Bailey court how he was followed by "packs of photographers" who always seemed to know his movements.

"I became aware that I was also turning up at places having arranged to go there secretly ... and the media were already there," he said.

The court also heard that a close member of Mr Law's family had been leaking information to the News of the World in return for payments in 2005.

Mr Law was questioned by a lawyer for former News of the World editor Andy Coulson, one of those on trial, about a story the newspaper ran that Ms Miller was having an affair with James Bond actor Daniel Craig.

Mr Law was asked if he was aware that a member of his "immediate family" was talking to the paper, which owner Rupert Murdoch shut down over hacking claims in 2011.

"I was aware later around 2011, maybe later than that ... that the News of the World had been in contact with people in my family, trying to find things out, asking for quotes," the actor replied.

Asked if he knew the family member was paid, he said: "I have never been aware of that."

Mr Law said that when he heard the rumours of Ms Miller's alleged affair, he telephoned Mr Craig to confront him.

But he told the court he could not remember whether that was before or after the paper broke the story, and he had not left a voicemail about it.

Mr Coulson's defence lawyer wrote down a name of an alleged source on a piece of paper to show Mr Law.

He replied: "I was made aware very recently that there had been some kind of communication with this person and several others in and around and about this period of time. I was never aware any money had been exchanged."

Former News of the World and Sun editor Rebekah Brooks is also on trial with Mr Coulson. They deny all charges.