Iraq's fugitive Vice-President Tareq al-Hashemi, a top critic of Prime Minister Nuri al-Maliki, was convicted of murder on Sunday and sentenced to death by hanging, in a decision likely to renew political tensions.

Hashemi, tried in absentia, has dismissed all charges against him as politically motivated. The court also tried his secretary and son-in-law Ahmed Qahtan in absentia and sentenced him to death.

The trial for the murder of a lawyer, a brigadier general and a top security official that opened in May covered the first of some 150 charges against Hashemi, who has been accused of running a death squad, and his bodyguards.

Sunday's hearing opened with the prosecution asking the court to condemn Hashemi, one of Iraq's most senior Sunni officials, to death for the first two murders but to drop a charge of involvement in the security official's killing.

The defence lawyers then read a lengthy closing statement protesting that the trial was unfair and the court exposed to political pressure.

A judge interrupted, warning the defence lawyer: "You are attacking the judicial authority and you will be held responsible if you continue."

The sentence was issued after about 30 minutes of deliberation by the three judges.

Hashemi himself met in the Turkish capital with Foreign Minister Ahmet Davutoglu on Sunday, in a meeting that was scheduled in advance but coincided with the sentencing, a senior diplomat in Ankara told AFP.

Born in 1942, Hashemi became one of Iraq's Vice-Presidents in April 2006, the same month that his brother and sister were shot dead in separate attacks.

When he first became a Vice-President, he was the head of the Iraqi Islamic Party, a group that was said to have connections to some elements of Iraq's Sunni insurgency following the US-led invasion of 2003.

The party was the driving force in Iraq's Sunni-led National Concord Front, which helped mastermind the return of the country's Sunni minority to the political process after the community boycotted January 2005 elections.

Hashemi later founded the Tajdid (Renewal) party, which is a part of Iraqiya, the secular, Sunni-backed bloc that won the most seats in 2010 parliamentary polls only to be outmanoeuvred by Maliki, who retained the premiership.

He was re-elected as Vice-President in 2010 but then accused of running a death squad in mid-December 2011 as the last American soldiers left the country.

Hashemi fled to Iraq's autonomous Kurdistan region, which declined to hand him over to the federal government, and then embarked on a tour that took him to Qatar and Saudi Arabia.

He has taken refuge with his family in Istanbul since April under the protection of the Turkish state which refuses to extradite him.

Interpol said in May that it had issued an international Red Notice for the arrest of Hashemi on suspicion of "guiding and financing terrorist attacks."

It said the notice, its highest possible alert, was issued under an Iraqi warrant "as part of an investigation in which security forces seized bombing materials and arrested individuals."

Hashemi's trial heard testimony that silenced pistols were found in raids on his house and that of his son-in-law, while bodyguards and other officials said they were offered money or coerced to carry out attacks on his orders.

Requests by Hashemi's lawyers for high-ranking officials to testify as character witnesses on his behalf were rejected, and his lawyers walked out of one session after a judge refused to accept their evidence.