Furious Lebanese judoka Nacif Elias accused Argentine opponent Emmanuel Lucenti of gamesmanship after he was disqualified for an illegal armlock at the Olympics on Tuesday.

Elias, a Brazilian fighting for Lebanon, was forced into a humble apology following a stunning tantrum when he was knocked out of the under-81kg category for a move on Lucenti that judges deemed illegal.

"In my opinion it was Argentine gamesmanship," said Elias in reference to an accusation Brazilians often throw at their bitter neighbours on the football field.

The furious fighter protested the decision and refused to shake hands with his opponent or leave the fighting area for some time after his opening under-81kg bout.

When he did eventually quit the mat, he screamed into a television camera, "I was robbed, this is not judo".

But he later returned to the mat alone and looking suitably repentant to bow to the dojo, the judges and the crowd, which gave him a standing ovation.

"I accept the International Judo Federation's decision," added Elias.

"But I apologise to the Brazilian fans, worldwide judo fans.

"We must have the philosophy of sport in our hearts, and the Olympic spirit, but I hope they understand me."

He added: "I ask for forgiveness, it wasn't behaviour fitting of an athlete."