The Hollywood actor condemned local officials for failing to rectify the problems in Flint sooner as residents have not had clean running water since 2014, when officials decided to draw from a river which has tested positive for lead.

He is adamant Michigan Governor Rick Snyder should step down over his handling of the crisis.

"At the very least he should resign. At the very least," Matt tells The Daily Beast. "Listen, everybody's entitled to a fair trial in the United States of America, but that man should get one. And soon. That's just my personal opinion."

Matt goes on to insist the problems in Flint are devastating for the local community, telling Sky News, "What is happening in Flint is really sickening, you know... We see these families, we see these children, and we think of our children... It's horrifying."

The Martian star, who founded a charity called to provide safe water and sanitation to deprived communities across the globe, even compares the situation in Flint to the problems in Ethiopia.

"We were in Ethiopia together six or seven years ago and this Flint thing has reminded me of this time in this little village where these kids were collecting this water that was about the colour of chocolate milk," he says. "Kind of like the water in Flint, actually. And they were filling up these little bottles with it to take it to school."

Pop superstar Cher has also been fighting to get clean water to Flint residents, and she has called for Governor Snyder to step down amid claims he initially played down the controversy and passed the blame on to other civil service officials.

She told, "He's just trying to save his a** now. He's only talking now 'cause he's at the end of his lie rope. It's such a gigantic problem, and the government is doing the wrong thing... Oh yes (he should step down), because I think taking complete responsibility is stepping down when you see what you've done. I mean, he knew what he was doing..."