His mother and stepfather confirmed the news via social media posts, revealing that he died on February 6. Coleman reportedly died suddenly after he collapsed while running. An official cause of death has not been released.
Coleman most famously starred in the 2005 family flick Nanny McPhee, as well as films It's Alive and The Fourth Kind.
The former child actor later studied science, worked as a conservationist and became a climate activist, changing his name to James "Iggy" Fox and working with Extinction Rebellion.
The organization has since shared an essay that Coleman wrote for their organization's newspaper.
In it, Coleman revealed that he had recently been arrested during an environmental protest in Brazil.
"I'm rebelling in love for this world and the wild," he wrote. "In compassion for the Indigenous, local and First Nations peoples who are persecuted protecting the ecosystems we all need to survive. In rage for the environmental defenders murdered every week — my siblings in the fight for life."
Read it in full here.
See his mother's Twitter post, including a link to Coleman's essay, below.
Rest in peace my beloved son Raphael Coleman, aka Iggy Fox. 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 https://t.co/qFRKPT7rRG— Liz Jensen (@LizJensenWriter) February 7, 2020