A reputed Russian crime boss has been shot dead by an unidentified gunman in central Moscow, in an apparent contract killing which may reignite a 'turf war' between crime rings. 

Aslan Usoyan, also known as 'Grandpa Hassan' was shot by a sniper on Wednesday afternoon as he was exiting an exclusive Moscow restaurant, and died while being rushed to a hospital.

Russian authorities conducted ballistics tests and said that motives could be "connected to the criminal activity of the victim and possible conflicts with other representatives of the same milieu". 

Police have said that the incident also left a female bystander wounded, who is being treated in hospital.

"I am sure that a new criminal redistribution will begin now," said Alexander Khinshtein, a Russian legislator who sits on the security committee, in a tweet. 

The Georgian-born Yezidi Kurd was targeted by a sniper in a previous attempt on his life in 2010. 

The 75-year-old earned the underworld title of "thief in law" which means a criminal godfather.

With his first conviction when he was aged 19, Usloyan allegedly headed a crime network involved in illegal gambling, drug and weapons sales, and natural resources extraction after the disintegration of the Soviet Union. 

Usoyan's ring was said to oversee the crime groups operating in south Russia, including the Caucasus.

Contract killings in turf wars were common across Russia when the Soviet Union collapsed as gangs battled to gain control of lucrative businesses and care up territory. 

Source: Agencies