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Actor Hugh Grant said Monday that he believes his phone was hacked by Britain's Mail on Sunday tabloid — the first time he has implicated a newspaper not owned by Rupert Murdoch in the wrongdoing.

Grant, star of "Four Weddings and a Funeral" and other movies, told an inquiry into media ethics that a 2007 story about his romantic life could only have been obtained through eavesdropping on his voice mails.

He said he could not think of any other way the newspaper could have obtained the story alleging that his romance with Jemima Khan was on the rocks because of his conversations with a "plummy voiced" woman the paper identified as a film studio executive.

Grant said there was no such woman, but he did receive voice messages from the assistant of a producer friend.

"She would leave charming, joking messages ... and she had a voice that can only be described as plummy," he said.

Grant sued the newspaper for libel and won.

Challenged as to whether he was speculating about the source of the story, Grant acknowledged that he didn't have any hard proof.

"Speculation? O.K. But ... I'd love to hear what the Daily Mail or the Sunday Mail's explanation of what that source was if it wasn't phone hacking."

Prime Minister David Cameron set up the inquiry into media ethics in the wake of a still-evolving scandal over phone hacking in Britain. Murdoch shut down the discredited News of the World tabloid in July after evidence emerged that it had routinely eavesdropped on the voice mails of public figures, celebrities and even crime victims in its search for scoops.

Grant is one of a string of high-profile witnesses, including actress Sienna Miller and author J.K. Rowling, who will testify about how they were followed, photographed, entrapped and harassed by tabloid journalists.

The first witnesses Monday were the parents of murdered teenager Milly Dowler, whose mobile phone voice mails were hacked after she disappeared in 2002.

Her mother told the inquiry that she believed her missing 13-year-old was still alive once she reached the girl's previously full voice mailbox.

Sally Dowler said when she could finally leave a message on her daughter Milly's voice mail weeks after the girl disappeared, she shouted: "She's picked up the voice mails! ... She's alive!"

In fact, messages on Milly's phone had been deleted by someone working for the News of the World tabloid while the Dowlers and the police were still searching for the girl, who was later found dead.

The Dowlers said they had been utterly shocked when police told them, much later, that Milly's phone had been hacked.

Sally Dowler said she "didn't sleep for about three nights."

"When we were given that information, it was terribly difficult to process it," she said.

Her husband Bob said he recognized immediately that the information was "dynamite." News that tabloid journalists had targeted not just celebrities but a murdered girl shocked many Britons and triggered a police investigation and media recriminations that are still unfolding.

The Dowlers took the stand together and spoke in quiet, composed voices during their 30 minutes of nationally televised testimony.

They described their shock and anger when a private walk to retrace their missing daughter's last steps was secretly photographed by the tabloid.

Sally Dowler said she and her husband Bob had no idea they were being observed as they walked near their home in May 2002, but days later saw the pictures in the News of the World.

"It just felt like such an intrusion into a really, really private grief moment," she said. The couple said they later realized that their own phone, as well as their daughter's, had been hacked.

More than a dozen News of the World journalists and editors have been arrested and several senior Murdoch executives have resigned over the still-evolving scandal. Two top London police officers also lost their jobs, along with Cameron's media adviser.

The inquiry, led by Judge Brian Leveson, could recommend major changes to the way the media in Britain are regulated.

The second witness Monday was journalist and novelist Joan Smith, whose phone was hacked while she was in a relationship with a politician, Denis MacShane. Smith said she was shocked when police said her name and details had been found in the notebooks of private eye Glenn Mulcaire, who worked for the News of the World and was jailed in 2007 for phone hacking.

"I don't think I'm somebody whose private life would be of much interest to the reading public," she said.

"This could happen to almost anybody. That's the astonishing thing. You don't have to be an incredibly famous actress or actor ... you just have to tangentially come into the orbit of somebody who is well known."

Graham Shear, a sports and media lawyer who has represented many celebrities, told the inquiry about the host of tabloid techniques he has encountered, from checkbook journalism to "kiss and tell girls" who target athletes.

Shear is suing the News of the World's parent company, alleging that his own voice mail messages, as well as those of his clients, were hacked.

He said tabloid journalism was "a business model that's become dependent and infatuated with sensationalist and titillating stories."

In that environment, he said, "the News of the World was at the front as the most effective story-gatherer."

Grant, a fierce critic of press intrusion, smiled for photographers as he arrived at the Royal Courts of Justice, where the hearings are being held.

Later this week the inquiry will hear from "Harry Potter" author Rowling, comedian Steve Coogan, actress Miller and former Formula 1 boss Max Mosley — whose taste for sadomasochism was revealed in a widely publicized News of the World sting.

It's a courtroom lineup that Britain's celebrity-obsessed tabloids would love, if only they weren't the ones in the dock.