Actor Hugh Grant told a British judicial inquiry Monday that he believes the Mail on Sunday tabloid must have hacked his phone, as it was the only way they could have come up with the material for a story they published in 2007.

It was the first time he has implicated a paper not owned by news tycoon Rupert Murdoch, a statement that came as part of a wide-ranging inquiry into media ethics in the United Kingdom that also included testimony from the parents of slain teen Milly Dowler.

Appearing before Judge Brian Leveson, Grant spoke about what he described as years of routine harassment by paparazzos after his first major hit movie, 1994's "Four Weddings and a Funeral." This included a strange break-in at his apartment in which nothing was stolen, but descriptions of the home later appeared in print.

He also detailed efforts to get the Mail -- owned by Associated Newspapers, a Murdoch rival -- to correct information it had published about him.

Appearing both candid and professional on the stand, the "About a Boy" actor said the 2007 story could only have been obtained through his voicemails -- which included a message about the yeast-spread Marmite from a "plummy-voiced" woman.

The paper identified the woman as a film studio executive and said it showed Grant's relationship with Jemima Khan was on the rocks. He sued the paper for libel and won, saying the information must have come from message left by a friend's assistant.

"She would leave charming, joking messages... and she had a voice that can only be described as plummy," he said, acknowledging he didn't have any hard proof of the story's source. "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."

The Mail on Sunday "utterly" refuted Grants claim that it hacked his phone, saying his comments were little more than smear attempts.

Later in his testimony, Grant described his attempts to keep his paternity of his newborn daughter a secret to spare the child's mother from harassment. He steered clear of the child's September birth to avoid drawing media attention. He dropped by the hospital the next day, and believes someone there leaked the news to the press.

"(The press) even knew the fake name she had checked into the hospital under," Grant told the inquiry.

Grant and the girl's mother, Tinglan Hong, are not together, but remain on good terms.

Grant also described his shock at seeing that details of a personal hospital visit had been published by The Sun and Daily Express.

It was "a gross intrusion of my privacy," he said. "I think no one would expect their medical records to be made public or to be appropriated by newspapers for commercial profit… That is fundamental to our British sense of decency."

He said he attempted to confront the paper about it and suggested they avoid a lawsuit by donating to a charity he supports, Health Talk Online.

"Seeing as they talked about my health online, I thought that was elegant," the actor quipped.

It wasn't the only light moment at the hearing. A few people at the inquiry reacted with smiles when the actor's full name -- Hugh John Mungo Grant -- was read aloud. Before the dashing actor began his testimony, Leveson warned that if he wanted a break, he wasn't required to say "cut," he could just ask.

Grant's appearance broke some of the tension in the room, which had just heard tragic testimony from Sally and Bob Dowler.

Dowler's mother told the inquiry that she still remembers the day in 2002 that she and her husband discovered someone had deleted messages from their missing daughter's phone. Sally Dowler believed it was a sign that daughter Milly was still alive.

But the missing girl's mother was mistaken, as it was a tabloid newspaper that had actually deleted the messages.

The Dowlers would eventually learn that the News of the World was hacking into their own phones, as well as the phone of their dead daughter.

The tabloid also followed the Dowlers on a day when they decided to retrace their missing daughter's last steps, before Milly was found dead, the inquiry heard Monday.

The Dowlers did not know they were secretly being followed by the paper, which published photographs of their walk days later.

"It just felt like such an intrusion into a really, really private grief moment," Sally Dowler told the inquiry.

Amid the Dowler case and other phone-hacking scandals at the News of the World, the decision was made to shut the paper down earlier this year. And owner Rupert Murdoch personally met with the Dowlers to personally apologize for what had happened to them.

"It was a very tense meeting," Sally Dowler said. "He was very sincere."

The Dowlers were the first witnesses to appear at the inquiry into media ethics in Britain, which was called by Prime Minister David Cameron after evidence surfaced that News of the World routinely hacked into the voicemails of public figures, celebrities and crime victims.

Next up was novelist Joan Smith, whose phone was hacked at a time when she was dating politician Denis MacShane.

Smith told the inquiry the fact that a tabloid sought to target her was an indication that the same thing could happen to anyone.

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

Other celebrities, including actor Sienna Miller and popular author J.K. Rowling, will appear before the inquiry in the days ahead.

With files from The Associated Press