The 31-year-old was last seen in July 2021.
He was reported missing following a crash on Old West Coast Rd, Darfield.
Linwood was last seen fleeing the scene of the crash on foot, towards the Waimakariri River.
"Police extends our condolences to his whānau and loved ones at this difficult time," said Syme.
Linwood's mother Sheree last night posted the news on her Facebook page.
"With a broken heart I'd like to let you all know that my son Joel Linwood's body has been found," she wrote.
"RIP Joel."
At the time of his disappearance, Linwood was facing criminal charges and was on electronically monitored bail.
It was alleged he cut off his bracelet and was being sought by police at the time of the crash.
Stuff reported Linwood sent his girlfriend a text message about the crash and then said he was "hiding".
Before Linwood's body was found a family member spoke to the Herald about him.
She said the family were upset that there had been "no search or publicity over his disappearance".
"Joel was never a saint but was very loved by his mum," she said.
"Joel's mum is so lost as she feels the police are not looking as he's a criminal and gang member.
"This is very hard for her family to watch."