A Qatari court has accused Russia of being behind the murder of a former Chechen leader there in February.
Yanderbiyev had spent the last three years in exile in Qatar
The judge made the charge as he handed down life sentences to two Russian agents convicted of killing Zelimkhan Yanderbiyev in the capital Doha.
He said the men had been acting on orders from the Russian leadership.
Russian Foreign Minister Sergei Lavrov has denied the men were involved in the killing, and said their lawyers would appeal against the decision.
Defence lawyer Dimitri Afanasiev told Reuters news agency that the men would also seek a transfer to Russia.
Qatari prosecutors had called for the death penalty during the closed-door trial, which began in April.
A life sentence in Qatar usually means 25 years.
The men were arrested shortly after Mr Yanderbiyev was killed when a device placed under his car exploded as he left a Doha mosque after prayers. His son was injured in the attack.
Russia insists the two men were in Qatar in order to gather anti-terrorism intelligence.
Correspondents in Moscow warned the trial threatened to cause a diplomatic breach between Qatar and Russia, particularly after allegations that the two agents were tortured to make their confessions.
Qatar expelled the first secretary of the Russian embassy in March over alleged involvement in the killing.
Mr Yanderbiyev was vice-president of Chechnya for most of the first war with Russian forces from 1994 to 1996.
Yanderbiyev had just returned to his car after Friday prayers
He took over the presidency when the leader of the Chechen independence movement, Dzhokhar Dudayev, was killed by a Russian missile in April 1996.
Russia had accused the former writer and poet of complicity in the incursions by Chechen rebels into the neighbouring republic of Dagestan in August 1999.
These incursions were later used partly to justify the return of Russian forces to Chechnya later that year.
It is believed that Mr Yanderbiyev and his family went to Qatar in January 2000.
On three occasions, Russia tried to have Mr Yanderbiyev extradited to stand trial on charges related to the events in Dagestan in 1999.
But no extradition treaty exists between Russia and Qatar, and the Qatari authorities said they believed Yanderbiyev would not face a fair trial.