TAMPA, Fla. (WFLA) – Raphael Coleman, the former British child actor who starred alongside Emma Thompson and Colin Firth in the 2005 film Nanny McPhee has died at age 25, Variety reports.

Coleman’s mother, Liz Jenson, confirmed his death in a statement on Twitter Friday.

“Rest in peace my beloved son Raphael Coleman, aka Iggy Fox,” Jensen wrote. “He died doing what he loved, working for the noblest cause of all. His family could not be prouder. Let’s celebrate all he achieved in his short life and cherish his legacy.”

His stepfather, Carsten Jensen, said on Facebook the actor “collapsed without prior health problems in the middle of a trip and could not be restored.”

When he was 10, Coleman played Eric Brown, one of seven rambunctious siblings in the movie Nanny McPhee. Emma Thompson played the tough-minded nanny who whipped the kids into shape.

Coleman later became an activist after studying zoology at the University of Manchester.

His mother shared an essay he wrote for the organization Extinction Rebellion’s, in which he explained why he turned to activism.

“As an activist my voice could be far more influential than it had been as a scientist,” he wrote.

“RIP Iggy Fox, aka Raphael Coleman,” his mother wrote in another tweet, “he knew that we are all already in Heaven, right here on Earth.”