James Desborough, an award-winning former reporter at the News of the World, has been arrested by officers investigating the phone-hacking scandal.

Desborough was arrested on suspicion of conspiring to intercept communications, contrary to section 1 (1) of the Criminal Law Act 1977, after arriving at a south London police station at 10.30am. He had arrived by appointment for questioning about criminal activities at the defunct paper.

The allegations are believed to relate to events before Desborough was promoted to be the NoW's Los Angeles-based US editor in April 2009, less than a month after winning a British Press Award for showbusiness reporter of the year.

His move to the US makes his arrest, the 13th made by Operation Weeting, particularly significant. If Desborough was involved in hacking while in Britain, it raises the question of whether he practised those techniques in the US – and if so, whether he was the first and only News of the World journalist in the US to do so.

It also has also emerged that Glenn Mulcaire, the private investigator at the centre of the phone-hacking affair, is suing the tabloid's publisher, News International, in an attempt to force the company to pay his legal bills. His lawyers have issued a high court writ after the company, part of Rupert Murdoch's News Corporation, announced on 20 July it would immediately stop paying his legal costs.

News International confirmed it had received the writ but had no further comment.

It is significant that Desborough is the most junior journalist to be arrested by police. Others arrested were senior editors, including Rebekah Brooks, Neil Wallis and Andy Coulson, who later became David Cameron's spin doctor.

If Desborough is charged with hacking, his relatively lowly status at the paper casts further doubt on NI's claims that the NoW phone-hacking problem was an isolated problem that ended in January 2007 with the jailing of its former royal correspondent, Clive Goodman, and Mulcaire.

At the 2009 British Press Awards ceremony, Desborough was praised by judges for his series of "uncompromising scoops which mean no celebrity with secrets can sleep easy". He was presented with his award by Jon Snow, the respected Channel 4 journalist and anchorman.

Desborough continued to win plaudits after his move to America. Ian Halperin, a Hollywood author, described him as someone who "never gets his facts wrong. He's a rock solid reporter."

Hollyscope, a website, also praised Desborough for "seem[ing] to have information that not even close family members know".

Desborough joined the News of the World in 2005 and broke stories including "Fern's big fat lie", which revealed that the former This Morning host Fern Britton's dramatic weight loss was the result of having a gastric band fitted, not exercise and sensible eating as had been thought.

Desborough was writing for the News of the World until it closed last month.

A source close to the investigation in the United States hinted that police in America would launch their own inquiry if Desborough was found to have engaged in illegal hacking activities.

"We would follow the logical story and if we believed that someone was involved then we would rely on our international partners to co-operate with that," the source said.

• Additional reporting: Paul Harris in New York and James Robinson