Robert Erb. (B.C. Lottery Corporation/HO)

Cannabis crusader Robert Erb is doing his part to legalize herb.

The marijuana advocate from Terrace, B.C., became $25 million richer after winning the Lotto Max jackpot on Nov. 2.

Now, the 60-year-old seasonal construction worker is pledging $500,000 towards the fight to decriminalize marijuana.

"The biggest social injustice I've seen in all my entire lifetime is the criminalization and prohibition of marijuana," Erb told CTV British Columbia on Friday.

Erb told the station he is pledging up to $500,000 to match donations made to Sensible B.C. over the coming months.

On its site, Sensible BC says it is working "to decriminalize the simple possession of cannabis in British Columbia through the Sensible Policing Act.

"The Sensible Policing Act would amend the Police Act, to redirect all police in the province from taking any action, including searches, seizures, citations or arrests, in cases of simple cannabis possession by adults."