Johnny Depp is planning a film about a former Russian security agent whose poisoning in London has touched off an international mystery, according to the trade magazine Variety — one of three possible Hollywood projects about the case.

One of the other projects, involving the director Michael Mann, came after Columbia Pictures agreed to pay $1.5 million for the film rights to a book about the former Russian agent, Alexander Litvinenko, being co-written by his widow and a close friend, the report said.

Warner Bros., which was outbid for that book, acquired the rights to a book by Alan Cowell, a New York Times reporter, which is expected to be published next year by Doubleday, Variety said. Depp's production company, Infinitum Nihil, will produce the film and the actor could star in it.

Mann is known for his crime sagas such as "Collateral," "Heat" and "Miami Vice," while Depp often takes on eccentric character roles in films such as "Pirates of the Caribbean," "Finding Neverland" and "Edward Scissorhands."

The report said Columbia envisions an espionage thriller "exploring the collision between the deep rooted Russian power structure enforced by the KGB ... and the new wave of wild west capitalism" that followed the collapse of the Soviet Union, Variety said. The book that will serve as the movie's main source is expected to be published in May by Simon & Schuster's Free Press imprint, the report said.

Braun Entertainment Group, based in Beverly Hills, Calif., said Saturday it had bought an option on film rights for a third potential project — based on Litvinenko's own book "Blowing Up Russia: Terror from Within."

Braun — which previously produced for "Freedom Road," a movie starring Muhammad Ali, said it was in talks with Litvinenko's widow, Marina, for its own project.

The former security agent's book was published in 2004 with financial support from the self-exiled Russian tycoon Boris Berezovsky and alleged the Russian Federal Security Service, or FSB — an agency that replaced the KGB — was behind bombings at Russian apartment buildings in 1999 that killed more than 300 people. The Kremlin blamed the attacks on Chechen separatists.

An updated version of the book will be released in Britain next week, the London publishing house Gibson Square said.

Litvinenko fled to Britain, was granted asylum and became a Kremlin critic in exile. The former FSB agent died in November, several weeks after falling ill with what was later determined to be poisoning by the rare radioactive isotope polonium-210.

Before his death, he said he fell ill after meeting in London with an Italian security expert to discuss possible suspects in the killing of the Russian journalist Anna Politkovskaya a month earlier. In her coverage of Chechnya, Politkovskaya was highly critical of alleged human rights violations by Russian forces and by Kremlin-backed Chechen officials.

Litvinenko blamed the Kremlin for his poisoning. Russian officials have denied that allegation. British and Russian authorities continue to investigate his death.