US actor RJ Mitte, best known for his role as the defiant son of drug kingpin Walter White in the drama series Breaking Bad, has died aged 34.

“It is with profound sadness that we share the tragic passing of beloved actor, philanthropist, and passionate disability rights advocate RJ Mitte,” his representative told the BBC.

He died in Brownsville, Texas. No immediate cause of death was provided.

Mitte, who lived with cerebral palsy, drew on his own experience for his role as Walter White Jr in the Emmy-winning drama series starring Bryan Cranston and Aaron Paul. He earned a Screen Actors Guild Award in 2014 for his work on the series.

“Mitte brought authenticity to the role and built a platform on disability awareness and inclusion,” his representative Sean Reilly said in a statement to the BBC.

Mitte also served as an ambassador for United Cerebral Palsy and Shriners Children’s.

He created The Mitte Foundation as well, to support philanthropic efforts and community initiatives, using his platform “to challenge stereotypes and promote greater representation for people with disabilities”, Reilly said.

The Brownsville Police Department confirmed the actor’s passing in a statement to the BBC, saying the cause and manner of death have not been determined and the investigation remains ongoing. No “foul play” was suspected, according to police.

The actor was declared dead on 12 October at what was believed to be his home, Cameron County Justice of the Peace, Cyndi Hinojosa, told the Associated Press, adding that an autopsy would be performed.

Breaking Bad aired on US cable broadcaster AMC for five seasons from 2008 to 2013.

The anti-hero drama created by Vince Gilligan earned a whopping 58 Primetime Emmy nominations and won 16, including two for Outstanding Drama Series in 2013 and 2014. It is widely credited as being one of the best US TV series of the 21st century.

Cranston plays a high school chemistry teacher in New Mexico who turns to a life of crime to support his family after a cancer diagnosis. As he descends deeper into the underbelly of the meth trade, he drifts further from his son, Walt Jr, who made his displeasure known with levity through much of the series.

Mitte, who grew up in Louisiana, was a young teen when he auditioned for the breakthrough role after moving to Los Angeles to support his younger sister’s acting career in 2005.

He has previously said that his first audition in Los Angeles was for a California state public service announcement for an anti-meth commercial.

“Fast forward to auditioning for Breaking Bad, which is still, in my opinion, an anti-meth thing because it doesn’t end well for anyone,” he said on the Joe Vulpis Podcast earlier this month.

His character was based on Gilligan’s late friend with a more severe case of cerebral palsy who used forearm crutches, which Mitte did not require.

He played the role with honesty and accessibility, cracking jokes as a teen whose health condition was never mentioned in the series.

After rising to prominence with the series, Mitte fought for more varied roles and complex depictions of characters with disabilities, both visible and invisible.

“Whenever awards season rolls around, we always hope to see a diverse group of projects that reflect all of us, in body and mind,” he told the BBC in 2021.

“Watching the awareness grow around disability representation has been great to see, but breakthroughs sometimes come in pieces and moments instead of larger change,” he said.

Mitte’s other on-screen credits include Hannah Montana, Switched at Birth, Westhampton and his latest project, Talking to Strangers, which came out earlier this year.

Additional reporting by Rebecka Pieder.