The father of activist adventurer Pete Bethune has died after a battle with asbestos-related cancer.

The anti-whaler was thought to be on coastline patrol in Africa when he was told his father, Donald Raymond Peter Bethune, had died.

Pete's mother Mary Russell-Bethune said her son had sent a eulogy to be read if he didn't make it back for the funeral on Tuesday.

"We don't even know what country Pete is in at the moment," she said.


"I don't know if he is in Africa or where he is. I have left a message on his cellphone."

Pete left a message on his Facebook page for his dad, who was one of his biggest supporters.

Don Bethune asked the Government to take a tougher stance on his son's behalf when Peter was charged with trespassing after he boarded the Japanese whaling boat the Shonan Maru 2 in 2010.

"RIP Dad. I've been on patrol with some people in a remote coastline and just got the news that Dad passed away 3 days ago," Bethune wrote.

"He was an amazing man in many ways. Super generous and always saw the best in people. We will all miss him dreadfully."

Mary Russell-Bethune said her family were at peace with Don's death.

It had been a tough year for the Bethune family. In January Pete's twin brother Barry Bethune saw his son Shaun Bethune, 23, and best friend Lindsay Cullen, 59, die of hypothermia in the icy waters of the Foveaux Strait after their boat capsized.

Don Bethune's funeral will be held on Tuesday at 1.30pm in the Avalon Chapel in Hamilton.