Top Russian criminal boss Aslan Usoyan, aka Grandpa Khasan, has been shot dead by a professional sniper with a collapsable precision rifle that can fit a briefcase.

Usoyan, 75, was shot in the head while leaving a restaurant in Povarskaya Street, central Moscow, and died in hospital after being rushed there by his bodyguards.

The sniper fired a total of six shots from a hidden location near the restaurant with a silenced 'Val' 9mm assault rifle, Ria Novosti reported.

Designed for Soviet Special Forces, once disassembled the rifle can fit a small briefcase and features a silencer and a muzzle flash reducer.

The weapon's stealth features made it impossible for Usoyan's bodyguards to locate the sniper, and they were forced to shoot blind when returning fire.

A waitress who was escorting the mob boss out of the restaurant was also hit by two bullets. According to LifeNews daily, the woman stepped into the sniper's firing line before the assassin could fire a second shot to Usoyan and secure the killing.

The sniper tried to force her out of the way by shooting her in the leg. However as the waitress remained upright and in the way the hitman again shot her in the chest. The woman is in a critical condition in a Moscow hospital.

Police later found the sinper's perch in a stairway on the sixth floor of a building on the opposite side of the street. There they retrieved three cigarette butts, six cartridges and a folding chair.

Georgia-born Usoyan had survived two previous assassination attempts during his long criminal career, in 1998 and 2010.

En ethnic Kurd, Usoyan contrloed a number of rackets in Moscow and across Russia, from prostitution to construction, facilitated by a multi-ethnic network of Georgians, Ingush, Chechens and Armenians.

"He built a very broad-based criminal network," Russian mob expert and New York University professor Mark Galeotti told the Washington Post.

"He was a classic gangster, like Corleone," Galeotti said referring to the character palyed by Marlon Brando in Francis Ford Copplola's movie The Godfather.

Aslan Usoyan
Russian mafia boss Aslan Usoyan, 75, was born in Georgia’s capital of Tbilisi (Facebook)