A Baghdad court sentenced Vice President Tareq Al-Hashemi, one of Iraq's top Sunni officials, to a fourth death sentence in absentia on Sunday over a foiled car bombing targeting Shiite pilgrims.

Hashemi, a prominent critic of Shiite Prime Minister Nuri Al-Maliki, has been out of the country since accusations he describes as politically motivated were first made against him in December last year.

The case has raised sectarian tensions in a country that only recently emerged from brutal communal bloodshed.

"Today, the court issued a death sentence against Hashemi and his son-in-law according to Article Four of the Anti-Terror Law in a case connected to an attempt to use a car bomb to target Shiite pilgrims," judicial spokesman Abdelsattar Bayraqdar said.

Bayraqdar said the attempted car bombing dated to December 2011 during Ashura commemoration ceremonies, when Shiite pilgrims walk along Iraq's highways to the shrine city of Karbala.

Hashemi's son-in-law, Ahmed Qahtan, is also his secretary and is last known to be in Turkey.

Bayraqdar and the head of Hashemi's defence team Muayad Al-Izzi said the death sentence was the fourth issued against the vice president since September.

Hashemi was on Thursday sentenced to death in connection with the assassination of a senior interior ministry official.

He was handed two death sentences in a hearing on 9 September in a trial connected to the murders of three other officials. The verdict was issued on the same day a wave of deadly attacks killed dozens of people nationwide.

Hashemi was originally accused of running a death squad in mid-December 2011 as the last US troops left the country.

He 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, and finally to Turkey.

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

At the time, 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.

Hashemi later joined 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.

In the earlier trial that resulted in his first death sentence, the court heard testimony that silenced pistols were found in raids on his house and that of Qahtan, 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.