Leading European filmmakers including the UK's Mike Leigh and Ken Loach have signed a letter to the Russian president expressing deep concern about a Ukrainian movie director, arrested on alleged terrorism charges in Crimea.
Spain's Pedro Almodovar and Wim Wenders, of Germany, are also among 19 signatories of the letter on Wednesday initiated by the Berlin-based European Film Academy (EFA), it said.
They said they were "deeply worried" about Oleg Sentsov, who, according to current information they said was arrested by Russia's FSB security force, the successor to the KGB, on May 11 in Crimea but later taken to a Moscow prison.
"There has not been any official information about the charges brought up against him for almost three weeks," an EFA statement said.
Addressed to President Vladimir Putin and other top Russian officials, the letter calls for Sentsov's safety to be ensured and for his whereabouts to be made public.
It also says the 37-year-old director should be charged "with a recognisable offence" or released and urges a "full, prompt and impartial" probe into his "apparently arbitrary detention".
Sentsov, an opposition activist and member of protest group AutoMaidan, lives in Crimea and presented his first feature film Gaamer about a computer-game obsessed teenager at the Rotterdam Film Festival in 2012.
In March, Russia annexed the disputed Crimea peninsula.
The FSB said at the end of last month that it would charge Sentsov and three others "shortly" with plotting "terrorist" attacks in Crimea.
If convicted of terrorism, they face jail terms of up to 20 years.
Others filmmakers to have signed the letter come from France, Poland, Hungary and Finland.
The EFA, whose origins date to 1989, brings together 3000 European film professionals to promote European film culture and holds annual awards.