AN Australian man has been accused of threatening to blow up a Russian plane on a flight from Japan to Moscow. Australian government officials today said a 28-year-old Sydney man had been arrested in Moscow, allegedly for trying to enter the cockpit of a Russian Boeing-777 Aeroflot plane travelling from Tokyo to Moscow. As the plane approached Moscow's Sheremetyevo international airport, the pilot alerted controllers that a passenger had threatened to blow up the plane, the ITAR-Tass news agency reported, citing an unnamed airport spokesman. "The Australian embassy in Moscow has verified the man's detention and will provide normal consular assistance," a Department of Foreign Affairs and Trade spokeswoman told AAP. "He's been detained by Russian authorities, he's been questioned as to his identity and his motives."An official at the airport told foreign news agencies: "The Australian-based passenger, born in 1976 and travelling from Sydney to Yerevan, Armenia via Tokyo and Moscow, tried to enter the pilot's cabin but was prevented from doing so by the crew." Reports by ITAR-Tass suggested the man did not have explosives and that he would undergo psychiatric tests. The Australian embassy in Moscow will help the detained man obtain a lawyer, the spokeswoman said.