The Business On... John Fredriksen, Shipping magnate

Should I know him?

He'd rather you didn't. Mr Fredriksen is one of those businessmen who is routinely described as a "secretive billionaire". Aged 67, Mr Fredriksen is a shipping magnate with a fortune Forbes puts at $10.7bn. He rarely speaks publicly and friends and colleagues safeguard his privacy. Still, you may be about to hear a lot more about him.

Why's that?

Regulators in the US are cracking down on what they regard as oil price manipulation. As part of that, they've just sued two trading firms owned by Mr Fredriksen. The allegation is that they made $50m by buying up so much oil that the markets began to think there was a shortage of supplies, driving the price up.

What does Mr Fredriksen say?

He calls the allegations "rubbish" and suggests the US authorities are interested in picking up some cheap publicity. "This is Obama having a go," he told a Norwegian paper yesterday.

Will the charges stick?

We'll have to see the Commodity Futures Trading Commission's evidence. But Mr Fredriksen, nicknamed "Big Wolf" in the shipping business, is a veteran of battles with the authorities. His run-ins with them go back to the Eighties when he had a lengthy legal fight in Norway over claims about his companies' activities.

What's his story?

He's a self-made man. The son of a welder, he grew up in Oslo and went to work for a shipping broker. Aged 27, he started out on his own and then made a fortune shipping oil during the Iran-Iraq wars in the Eighties. His businesses have carried on expanding ever since, with one analyst describing him as a "modern-day Onassis" – though actually, his fleet of tankers is now much bigger than the famous Greek tycoon's empire.

Anything else?

He gave up his Norwegian citizenship a few years ago and is now a Cypriot passport holder. Based in London, he's a big football fan who was once linked with a bid for Spurs. A widower, he has twin 27-year-old daughters who are said to be increasingly involved in his business.