"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".
Joel Linwood went missing in July last year after fleeing the scene of a crash. His body was found near a North Canterbury river this month. Photo / Facebook
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.