Australian Touring Car Championship winner John Bowe has been diagnosed with prostate cancer.

The two-time Bathurst 1000 winner announced his diagnosis via social media.

The 66-year-old said he was feeling fine and had no signs associated with the illness, but will begin undergoing treatment on Tuesday.

Bowe has long been an advocate for physical and mental wellbeing, opening up in recent years about his depression battle.

“Time to shift the focus away from motorsport and talk men’s health again for a moment,” Bowe wrote.

“Remember a while ago I encouraged all men over 40 to get yearly check ups regarding Prostate Cancer? Well guess what? I have been, and have now been confirmed to have it.

“I feel fine and have no signs, but it’s there and I must do something about it! So don’t put it off just because you don’t feel any symptoms.

“I’m having my first treatment on Tuesday at the new Peter McCallum Cancer Clinic in North Melbourne. After that I’m not sure because there are several options.”

The announcement comes just weeks after Bowe notched up his 100th win in the Touring Car Masters, a series he has won five times.

In light of the announcement, Bowe said he is unsure if he will contest all the remaining rounds in this year’s Touring Car Masters.

“As our Touring Car Masters season continues at Bathurst in a few weeks time, I’m unsure of what effect it will have on that,” he continued.

“But I’ll be racing at the Mountain come hell or high water!! I’ve never been one to pass up an opportunity to drive at that amazing racetrack!!”

Bowe twice won the Australian Drivers’ Championship in 1984 and 1985 in a Ralt RT4.

He later made the shift to tin tops, racing in the Australian Endurance Championship and Sports Car Championship.

Bowe made his Australian Touring Car Championship debut in 1986, claiming two podium finishes in a part-time campaign.

After a one-year hiatus, Bowe returned in 1988 to race alongside Dick Johnson in a Ford Sierra. That year he finished runner-up to his team-mate.

His first major success with the team came in 1989, winning the Bathurst 1000 with Johnson in their Sierra.

Another Bathurst 1000 win came in 1994, again with Johnson, though this time in an EB Falcon.

Bowe would continue racing in the Australian Touring Car Championship with Dick Johnson Racing, finally earning the championship crown in 1995 in an EF Falcon.

Bowe has twice won the Bathurst 12 Hour in the production era (2010) and current GT3 period (2014), the latter with Craig Lowndes, Peter Edwards, and ex-Formula 1 driver Mika Salo.