Who is Chernak from The Bourne Identity and what is their importance?

Chernak is a an important member of the underworld in Zurich. Wheelchair bound, Bourne kills Chernak in his apartment in the Löwenstrasse. During World War II, Chernak was a prisoner in Dachau, a German concentration camp. While imprisoned, he was recruited to interrogate one of the other prisoners. Cain uses Chernak to arrange his contracts.