Mark Richardson, leader of the Inch drug gang in Edinburgh, was jailed for 10 years in August 2010 over a £2 million cocaine and heroin haul.
It is claimed that Richardson was attacked while in Glenochil Prison, Clackmannanshire, by a rival dealer from Glasgow with a homemade blade.
Advertisement
Hide AdAdvertisement
Hide AdA source said: “It was horrific. His face was cut wide open and you could see his teeth.”
The Scottish Prison Service did not comment.