Qatari prosecutors have demanded the death penalty for two Russian agents accused of murdering a Chechen rebel leader, defence lawyers said.
The trial has taken place amid tight security
The court trying the case said it would hand down its verdict on 30 June.
Russia has denied any involvement in the killing of Zelimkhan Yanderbiyev and says the pair were in Qatar to gather anti-terrorism intelligence.
Prosecutors were summing up their case behind closed doors on Tuesday, defence lawyers said.
Correspondents in Moscow say the trial threatens to cause a diplomatic breach between Qatar and Moscow, particularly after allegations that the two agents were tortured to make their confessions to the February bombing.
Lawyer Ilya Levitov said prosecutors had tried to disprove that torture was used against the Russian pair.
"They argued that the confessions were made four days after the arrest and said that, if torture had been used, they would have confessed earlier," he said.
Mr Yanderbiyev, who was acting president in 1996-97, fled Chechnya in 1999 after the Russian invasion and went into exile in Qatar.
The accused were arrested shortly after the explosion, caused by a device placed under Mr Yanderbiyev's car as he left a Doha mosque after prayers.
Moscow had sought Mr Yanderbiyev's extradition from Qatar on charges of terrorism and links to al-Qaeda.