MOSCOW — Russian billionaire Alexander Lebedev, owner of two leading British newspapers, punched a man in the face during a television debate on the financial crisis to be aired on Sunday.

A clip posted on the NTV television channel's website shows Lebedev, a former KGB agent who has made a fortune in banking, landed a right jab to the face of ex-real estate baron Sergei Polonsky.

Lebedev knocked Polonsky off his chair, and threw another punch as Polonsky tumbled off the back of the studio's elevated platform, but the second punch failed to connect.

Just before Lebedev pounced, Polonsky told the other guests he wanted to "stick one in the mouth."

On his blog, Lebedev justified the assault by saying Polonsky had behaved in an aggressive, threatening manner throughout the debate.

"In a critical situation, there is no choice. I see no reason to be hit with the first shot. I neutralised him," the owner of Independent and Evening Standard newspapers said.

Lebedev also co-owns liberal Russian newspaper Novaya Gazeta with ex-Soviet leader Mikhail Gorbachev.

Polonsky, who used to head the Mirax Group real estate firm, got up quickly and did not appear injured, but later published online pictures of a cut on his arm and his torn trousers.

Polonsky's business nosedived after the onset of the 2008 global financial crisis, forcing him to abandon work on Muscow's Federation Tower, which he hoped would become the tallest building in Europe.