"I'd like to thank the Cowboys for their unwavering support – they could not have done any more for me, particularly the medical staff – as well as the club's members and fans for their well wishes."
Martin played four tests for New Zealand after making his international debut in 2016. He made 49 appearances for the Cowboys and 13 for the Panthers after impressing as a rookie in the 2016 season before heading north.
Cowboys Director of Football Peter Parr spoke glowingly about Martin when farewelling the Kiwi international.
"We'd like to thank Te Maire for everything he's done for the club. He's been a wonderful contributor since he's been here, he played in a grand final and off the field has had a significant impact on everyone at the club," Parr said.
"It's always sad when someone of his age has to retire, but there's also positives in that he's made significant improvements in his health. We've been given every indication he'll be able to live a normal life and that is far more important than him playing football.
"We're sad to see Te Maire go given he's such a great bloke, but he'll always be welcome at our club and we'll never forget what he's done for us in his time here."
