Self-described "conservative warlord" and Coalition Senator Barry O'Sullivan has thrown his support behind a push to legalise medical cannabis, and expressed confidence Federal Parliament would support the reform.

Mr O'Sullivan, a former drug squad detective, said his "mind had opened up considerably" over the course of a Senate inquiry on proposals drafted by Greens Senator Richard Di Natale.

Mind opened: Barry O'Sullivan said he had been moved by testimony from people who had sourced cannabis illegally in a bid to ease the suffering of loved ones. Credit:Alex Ellinghausen

Senator Di Natale's bill would create an independent body of experts, the Office of Medicinal Cannabis, which would license commercial growers and determine how cannabis could be prescribed and dispensed.

Mr O'Sullivan said he had been moved by testimony from people who had sourced cannabis illegally in a bid to ease the suffering of loved ones.