Illegal voicemail interception and cell phone tracking was a matter of routine at both The Sun and the News of the World tabloids, the brother of a whistle blower at the center of Britain's phone hacking scandal said Monday.

Stuart Hoare — the brother of the late journalist Sean Hoare — told an inquiry into British media ethics that both papers, published by Rupert Murdoch's News International Ltd., broke the law as part of their "daily routine."

"The reality was that phone hacking was endemic within the News International group," Hoare said in a witness statement published to the inquiry's website. "I know this to be the case because Sean and I regularly discussed this and there are emails in existence which support Sean's description of a practice referred to during such meetings as 'the dark side.'"

Sean Hoare was the first ex-News of the World journalist to publicly accuse his former editor Andy Coulson of being at the hub of a culture of wrongdoing at the paper, an allegation that helped ignite the scandal that forced Murdoch to close the British tabloid. Coulson eventually had to resign his post as a senior aide to Prime Minister David Cameron because of the scandal.

Sean Hoare, who suffered from drinking problems, died in July, just as the scandal was exploding. Stuart Hoare told the inquiry Monday that he was testifying because he and Sean "shared a lot of secrets and I felt very, very strongly that someone had to represent my brother."

The inquiry, led by Lord Justice Brian Leveson, was set up in response to the scandal to examine the culture and ethics of Britain's press.

So far the scandal has largely centered on wrongdoing at the News of the World, where journalists intercepted voicemails, hacked into computers and bribed police in an effort to win scoops. But the shadow of suspicion has fallen across other papers as well, including The Sun, Britain's top-selling daily.

Last month lawmakers investigating the scandal published a 2008 email drafted by a News International legal adviser warning that journalists implicated in illegal practices had secured "prominent positions" at The Sun. Also in November, an award-winning reporter Jamie Pyatt became the first Sun journalist to be arrested on suspicion of police bribery.

Hoare said that reporters at the Sun regularly hacked into phones and engaged in a practice dubbed "pinging," by which police were bribed to trace the location of people's cell phones.

"I have been asked not to name names," Hoare said in his statement. "But those involved know who they are and what they have done."

Hard evidence of wrongdoing at The Sun could further shake Murdoch's beleaguered British holdings. The Australian-born tycoon bought the paper in 1969 and it has long served as a conduit for influencing British politics.

If The Sun is sucked into the scandal it could further dent the paper's clout — and hurt its ability to prop up Murdoch's money-losing Times and Sunday Times newspapers.

Rupert's son James, himself under fire over the scandal, has refused to comment on whether he would close The Sun if it was proven that journalists there broke the law.