A Ukrainian film director went on trial on terror charges in southern Russia on Tuesday, after Moscow held him for more than a year in a case decried by Kiev, rights groups and prominent film directors across the globe.

Oleg Sentsov flicked a victory sign at several dozen supporters and reporters as he filed into the defendant cage in a military courtroom in the city of Rostov-on-Don.

The pro-Kiev film maker -- along with a second defendant Alexander Kolchenko -- is accused of plotting and carrying out "terrorist attacks" on the Crimea peninsula after the region was seized from Ukraine by Russia last March.

"I don't consider this court a court at all, so you can consider whatever you want," Sentsov said in court.

Both men deny the charges against them in a case that has sparked international condemnation from rights groups and concern from award-winning international directors.

Sentsov, 39 -- a resident of Crimea who faces up to 20 years if found guilty -- was arrested in the region's main city Simferopol in May by Russia's FSB security service for allegedly organising a group of saboteurs that plotted attacks and targeted pro-Moscow organisations.

"The court will question a number of witnesses and victims," court spokeswoman Alyona Katkalo told journalists.

A lawyer for the director said he had little hope that his client would get a fair hearing and that the best outcome would be for Sentsov to be sent back to Ukraine in a prisoner swap.

"I think the result will be negative. No one will acquit anyone, no one will change any charges," lawyer Dmitry Dinze told AFP.

"We hope that when all the procedures are done, Sentsov will be exchanged for some other people in Ukraine who are important to Russia."

Two of Sentsov's alleged co-conspirators have already been found guilty of participating in the group and sentenced to seven years in prison.

Ukraine and Russia have been locked in a bitter feud since Moscow's seizure of Crimea, with Kiev and the West accusing the Kremlin of fuelling a subsequent separatist conflict in the east of the country.

Ukrainian President Petro Poroshenko called for Sentsov's immediate release in a phone call last week with German Chancellor Angela Merkel, French President Francois Hollande and Russian leader Vladimir Putin.

Sentsov presented his first feature film, "Gamer", about a computer-game obsessed teenager, at the Rotterdam Film Festival in 2012.

Top film directors including Spain's Pedro Almodovar and Britain's Ken Loach have previously expressed concern for Sentsov in an open letter to Putin.

Sentsov is one of several high-profile Ukrainians currently facing trial in Russia, including female helicopter pilot Nadezhda Savchenko, whose detention has become a cause celebre in her homeland.

Putin denied during his annual phone-in in December that Savchenko and Sentsov are Ukrainian prisoners of war.