The woman at the centre of the Lawyer X scandal was involved in a sexual relationship with a former police officer, who was later on a steering committee that managed her role as Informer 3838.

The oversight role of the senior officer, who was part of the force's Intelligence and Covert Support unit, raises further concerns about force's handling of a highly sensitive matter already riddled with conflicts of interest.

Informer 3838 is the registered number police gave the gangland lawyer when she turned supergrass and gave police information about Melbourne's criminal underworld, some of which were her own clients.

The Age understands the lawyer and policeman began an intimate relationship when the officer worked as a prosecutor. They met at a readers course, in which barristers and prosecutors hone their court skills.

After a stint with the Australian Federal Police, the officer rapidly advanced through the ranks, and is understood to have been closely aligned with former chief commissioner Simon Overland.