The Japanese American man Newsweek magazine claims is the founder of Bitcoin has denied he had anything to do with the digital currency.

In an exclusive two-hour interview with the Associated Press news agency on Thursday, Dorian Nakamoto, 64, said he never heard of Bitcoin until his son told him he had been contacted by a reporter three weeks ago.

Reached at his home in Temple City, east of Los Angeles, Nakamoto acknowledged that many of the details in Newsweek's report are correct, including that he once worked for a defence contractor.

But he strongly disputes the magazine's assertion that he is "the face behind Bitcoin".

Since Bitcoin's birth in 2009, the currency's creator has remained a mystery. The person - or people - behind its founding have been known only as "Satoshi Nakamoto", which many observers believed to be a pseudonym.

Reuters news agency reported on Thursday that Nakamoto, a reclusive multi-millionaire, emerged from his modest Southern California home and denied involvement with Bitcoin before leading reporters on a freeway car chase to the local headquarters of AP.

In its story, Newsweek included a photograph and a described a short interview, in which Nakamoto said he was no longer associated with Bitcoin and that it had been turned over to other people.

The magazine concluded that the man was the same Nakamoto who founded Bitcoin.

Mobbed by reporters

Dozens of reporters, including a sprinkling of Japanese media, encircled and camped outside the two-storey house in Los Angeles on Thursday morning, accosting the mailman and repeatedly ringing the doorbell, to no avail.

Police vehicles drove by several times but did not stop. Several times, someone pulled back the drapes on an upstairs window.

In the afternoon, the silver-haired, bespectacled Nakamoto stepped outside, dressed in grey sport coat and green striped shirt, with a pen tucked in his shirt pocket.

Fans see Bicoin as a digital world currency [Reuters]

He was mobbed by reporters and told them he was looking for someone who understood Japanese to buy him a free lunch.

"I'm not involved in Bitcoin. Wait a minute, I want my free lunch first. I'm going with this guy," Nakamoto said, pointing at a reporter from AP.

"I'm not in Bitcoin, I don't know anything about it," the man said again while walking down the street with several cameras at his heels.

He and the AP reporter made their way to a nearby sushi restaurant with media in tow, before leaving and heading downtown.

Joe Bel Bruno, a Los Angeles Times reporter, followed the pair and described the chase in a running stream of tweets.

Eventually, the pair dashed into the AP offices in the business district of Los Angeles, where reporters were still waiting for Nakamoto to emerge.

Fans see Bitcoin as a digital-world currency beyond the government interference, while critics, whose ranks increased with the recent closure of a major bitcoin exchange, see a risky investment whose anonymity aids drug dealers and other criminals.

Nakamoto kept a low profile in part to avoid attention of authorities, Newsweek said, and indeed on Thursday the office of Benjamin Lawsky, superintendent of New York's Department of Financial Services, was keen on speaking with him, a source familiar with the situation told Reuters.

Peer-to-peer network

Bitcoin is bought and sold on a peer-to-peer network independent of central control.

Its value soared last year, and the total worth of bitcoins minted is now about $7bn.

In the Newsweek article, Nakamoto was credited by Bitcoin's chief scientist, Gavin Andresen, in working out the first codes behind the currency.

A man of few words who refused to discuss anything beyond the currency or even communicate outside of email, Nakamoto was described by his brother in the Newsweek article as "fickle and has very weird hobbies", including a penchant for model trains.

Nakamoto displayed an unusual aptitude for math as a child. He immigrated with his mother to California in 1959.

He was worked for defence and electronics company Hughes Aircraft, but never discussed work because much of it was classified, according to Newsweek interviews with several friends and relatives.

"He's very focused and eclectic in his way of thinking. Smart, intelligent, mathematics, engineering, computers. You name it, he can do it," Newsweek quoted Arthur Nakamoto, his younger brother, as saying.

Newsweek estimates Nakamoto's wealth at $400m.