Former MC5 manager John Sinclair has died, aged 82.

His representative, Matt Lee, confirmed the late poet and political activist’s passing this morning (April 2) at Detroit Receiving Hospital following congestive heart failure, reports The Detroit News.

Sinclair was an influential activist who was best known for his fight toward legalising marijuana in the US and for his role in MC5. The Davison native was also a champion of civil rights and co-founder of the radical anti-racist group the White Panther Party.

The late activist also helped launch Iggy Pop And The Stooges. Pop was one of the first to pay tribute to Sinclair following his passing.

“He was a truly interesting man, one of a kind. Thanks and praises,” he wrote on X.

Billy Fuller, Robert Plant‘s bassist, also paid his respects. He wrote: “RIP John Sinclair… I met him once when I was asked to bring some smoke for him before his gig at the Thekla in 2002. He signed my copy of kick out the jams as a thank you.”

Sinclair was famously arrested for allegedly giving two cannabis joints to police officers in the late 1960s and sentenced to 10 years in prison.

He served 29 months but was released a few days after John Lennon, Stevie Wonder, Bob Seger and others performed in front of 15,000 attendees at the University of Michigan’s Crisler Arena. Lennon also wrote a song named after Sinclair.

Over the years, Sinclair also promoted concerts and festivals and helped to establish the Detroit Artists Workshop and Detroit Jazz Center. He taught blues history at Wayne State University and wrote liner notes for albums by artists including The Isley Brothers and Harold Melvin & The Blue Notes.

His death comes just two months after MC5 guitarist and co-founder Wayne Kramer died at the age of 75 after battling pancreatic cancer.