Bas Rutten, GTA Wiki

Sebastiaan "Bas" Rutten is a voice actor and character who appears in Grand Theft Auto IV, Episodes from Liberty City, and mentioned in Grand Theft Auto: Chinatown Wars. He is a real life former Dutch UFC Champion and helped with motion capture of Niko Bellic's fighting during the making of Grand Theft Auto IV. Bas was in the movie "Here Comes The Boom", a comedy where he plays a character named Niko, which the film's director admitted was a reference to Niko Bellic. Bas has openly admitted that

GTA IV': A walk on the pacifist's side

Bas Rutten reveals he was afraid to face Antonio Inoki

Found this on Bas Rutten was a beast back in the day. : r/MMA

Bas Rutten on GTA 4 Cameo, Doing The In-Game Fight Sequences!

Roman Bellic - Grand Theft Wiki, the GTA wiki

Bas Rutten - Bio, Age, Net Worth, Height, Career, Married, Facts

Decipher SciFi

The Men's Room With Bas And Jeremy - Grand Theft Auto Ⅳ(グランドセフトオート４)GTAⅣ攻略 wiki - atwiki（アットウィキ）

Bas Rutten, Grand Theft Encyclopedia

Grand Theft Auto IV (Video Game) - TV Tropes

Bas Rutten screenshots, images and pictures - Giant Bomb