The suspect Auckland Police are searching for over the fatal stabbing on a Onehunga bus was recently convicted for threatening to kill

The public are urged to keep an eye out for 37-year-old, Kael Leona .

Police say it appears the victim and suspect - did NOT know each other.

Our newsroom understands Leona was sentenced in May for threatening behaviour.

He received one year and seven months in prison - but was released later this year on parole.

Court documents also reveal he was due in court today, for obstructing and resisting a police officer.

Acting Detective Inspector, Alisse Robertson says they believe he's still in the Onehunga - Mount Wellington area.

She says he's known to Police and they're seeing if his previous history contributed to what's happened.