Of all of Rupert Murdoch’s loyal lieutenants, none is more loyal, nor longer-serving, than Leslie “Les” Hinton.

A British citizen by birth, Hinton, like Murdoch, is a naturalized American who has been in Murdoch’s employ since he was a teenage copyboy at the media baron’s first newspaper, the Adelaide News in Australia. Among his duties then: fetching the boss’s lunch. As Murdoch marched around the globe acquiring news and entertainment properties, Hinton has been at his side. In all, he has spent 50 of his 67 years helping Murdoch build his conglomerate, News Corp.

Now Hinton’s role in one of Murdoch’s darkest passages is being called into question.

As a phone-hacking scandal continues to roil Murdoch’s operations in Great Britain, the spotlight has turned on Hinton, currently the chief executive of one of the jewels of News Corp.’s U.S. operations: Dow Jones & Co., publisher of the Wall Street Journal.

As the head of Murdoch’s British newspaper division, News International, from 1995 to 2007, Hinton oversaw the News of the World, the newspaper that allegedly pried into the phone accounts of hundreds of celebrities, politicians and ordinary Britons. Hinton testified before Parliament about the matter twice, insisting that the illegal activity had been the actions of a single rogue reporter.

The hacking story took another downward turn for Murdoch on Monday with allegations that his British papers targeted former British prime minister Gordon Brown before and during his term in office.

According to the Guardian newspaper, the hacking of Brown’s voice mail, bank account, legal files and family medical records involved not just his now-defunct tabloid, News of the World, but also Murdoch’s other British papers, the Sun, Times of London and Sunday Times.

The emerging question is whether Hinton knew about illegal activity at the newspapers under his watch. He has strongly denied that he did.

When he testified before a Parliament committee in March 2007 as head of News International, Hinton said he was “absolutely convinced” that the hacking was limited to one News of the World reporter. He didn’t identify the reporter, but it was clear he meant Clive Goodman, the paper’s royals correspondent, who had pleaded guilty to receiving information surreptitiously obtained from the phones of royal staff members.

At the time, Hinton also defended then-news editor Andy Coulson in his testimony. “I believe absolutely that Andy did not have knowledge of what was going on,” he said. Coulson, who resigned from the paper amid the scandal and later became spokesman for Prime Minister David Cameron, was arrested Friday on charges related to the hacking investigation.

Hinton was one of five News International executives who had access to an internal investigation in 2007 that disclosed that the illegal behavior at News International’s newspaper was broader than the company had acknowledged up until that time, the Guardian reported Monday.

In 2009, Hinton testified before another Parliament committee that News International had gone to “extraordinary lengths” to investigate itself and had disclosed its findings. “There was never any evidence delivered to me that suggested that the conduct of Clive Goodman spread beyond him,” he said then.

Public revulsion over the hackings prompted Murdoch’s son James, one of Hinton’s successors at News International, to announce the closure of the News of the World last week after 168 years in operation.

The younger Murdoch seemed to have Hinton in mind when he said in the newspaper’s closing announcement: “The paper made statements to Parliament without being in the full possession of the facts. This was wrong.”

Hinton could not be reached for comment Monday. A spokeswoman for Dow Jones said the company had no comment.

Hinton, a former editor and reporter for Murdoch-owned newspapers who was once injured while covering the conflict in Northern Ireland, has maintained a relatively low profile over the years, deflecting glory as well as criticism to Murdoch, 80. As a businessman, Hinton’s loyalty has been amply rewarded with senior postings within News Corp. Among others, he has headed the Fox TV station group, TV Guide and the British newspaper division. He took over Dow Jones after Murdoch bought it in 2007.

Attesting to the often intertwined nature of the British political and media worlds, Hinton in 2009 married Kath Raymond, a onetime adviser to Brown, the former prime minister.

“Rupert would not be where he is today if he had not recognized talent,” Boston Herald publisher Patrick Purcell said in introducing Hinton, an old friend, before a speech to an executive club in March.

Hinton was only too happy to echo the accolade. “If Rupert Murdoch asked me to get his lunch,” he said in his speech, “I still will.”