A man who gained widespread attention for his exposure of Scientology has passed away. 

The Daily Mail reports that Mike Rinder passed away recently at the age of 69.

This comes just about 18 months after he was diagnosed with cancer. According to the outlet, he had an advanced form of esophageal cancer.

It was his wife, Christie Collbran, who announced his passing.

Who is Mike Rinder?

What made Rinder's whistleblowing so powerful is that he himself was a former scientologist. And, not only that, but he actually, at one point, was one of Scientology's chief proponents.

Florida Politics reports:

Rinder climbed to some of the highest ranks within Scientology, working alongside leader David Miscavige as a top church spokesperson. He joined the church as a child along with his parents who, despite his acceptance into the University of Adelaide, pushed him to instead join the elite Scientology group Sea Org, which traveled with Scientology founder L. Ron Hubbard . . .

As such, he got to see the inner working of the group, and, clearly he did not like what he found out.

Rinder was the source for a series of Tampa Bay Times reports that exposed Scientology. "Rinder was a top source for the paper in its three-part series revealing abuse and other rituals used to keep church critics at bay, called “The Truth Rundown," the outlet reports.

Upon leaving Scientology, Rinder also lost his wife and children, who chose not to go along with him.

A sad end

After leaving Scientology and his family, Rinder went on to marry Collbran, and it was with her that he spent his final days.

The Daily Mail reports:

Mike Rinder, 69, passed a year-and-a-half removed from his advanced esophageal cancer diagnosis, and shortly after sharing a photo with his wife and two kids over Christmas. In the snap, a smiling Rinder looks a far cry from the man seen next to wife Christie Collbran in photos shot just a few months ago, where the Australian-born defector still had a full head of hair and a healthy complexion.

The outlet goes on to report that Collbran "paid tribute" to Rinder over the weekend.

She wrote, ''Rest in peace, my sweet, beautiful husband."

She added, "You have been the pillar of stability in our lives, filling our days with your strength, wisdom, love, laughter and devotion. The world will remember you. My best friend, my hero, my love, Michael John Rinder."