A Turkish policeman has been jailed for seven years and nine months after being convicted of shooting dead a protester during 2013 anti-government protests, a verdict denounced as lenient by relatives of the victim.

With several similar cases pending, the trial of Ahmet Sahbaz was seen as a crucial test of the authorities' willingness to prosecute police brutality under President Recep Tayyip Erdogan.

On Wednesday, the court found Sahbaz guilty of killing 26-year-old Ethem Sarisuluk in Ankara last year at the start of three weeks of clashes between police and protesters that convulsed the country.

There is nothing more to say. The justice system bolstered the murder. This proves it is legitimate to kill people on the street. Sarisuluk's brother Mustafa

The verdict sparked tumultuous scenes in the courtroom, with supporters of the victim shouting "murderer state" and slamming the judge for being too lenient.

"There is nothing more to say. The justice system bolstered the murder. This proves it is legitimate to kill people on the street," Sarisuluk's brother Mustafa told the AFP news agency.

"The murderer will be among us five years later," he said, anticipating an early release for Sahbaz. He said that the family would appeal the verdict.

The victims' supporters initially applauded the verdict when the court announced a life sentence for murder.

However, as is customary under Turkish law, Sahbaz received reductions to his sentence due to attenuating circumstances, as the court agreed he was provoked by the protesters.

Sarisuluk's supporters showed their derision by throwing bottles across the courtroom.

Kerem Altiparmak, professor of law at Ankara University, slammed the verdict saying it was "a method of impunity the same as an acquittal".

Emotional hearing

Sarisuluk was one of at least eight protesters killed nationwide in the police crackdown during the protests against Erdogan's government.

At an emotionally-charged verdict hearing earlier, Sahbaz described how he had been pelted with stones by protesters and said he had been going through emotional turmoil since the killing.

Sahbaz, who has been in jail for one year pending trial, disguised himself by wearing a wig and a fake moustache in the initial hearing last year.

"You cannot understand the fear, panic inside me since the trial began in September 2013," he told the court.

"I am a 28-year-old man trying to make a living. There can be no device that measures the storm inside me," he said.

Sahbaz said he fired two shots in the air and the third hit the protester because of the chaos at the scene.

The protests began as a grass roots movement against plans to build a shopping mall on Gezi Park on Taksim Square in Istanbul, one of the rare green spaces in the centre of the city.

But they quickly snowballed into mass demonstrations nationwide by mainly secular Turks angry at the authoritarian tendencies of Erdogan's Islamist-rooted government.