Police have released photos of Shannon Baker and revealed his car was last seen in Auckland on Monday night.

Fifty-five-year-old Baker was found dead at an address on Calgary St in Sandringham on Tuesday morning with police saying they are treating his death as a homicide.

They have appealed for help with their investigation from the public calling on anyone who may have seen Baker's green Mercedes - registration FCG929 - to contact them.

The car was last seen exiting the Northwestern motorway at St Luke's on Monday at 10.25pm.

Police also today released a photo of Baker.

Shannon Baker was found dead at an address in Sandringham on Tuesday morning. Photo / Supplied

"We are working to piece together what happened in the lead up to his death and want to hear from anyone who was in recent contact with Shannon or may have seen him on Monday night," Detective Inspector Aaron Pascoe said.

He said any information could be vital to the investigation.

Pascoe earlier said Baker's family was extremely upset at his death and had requested privacy.

Anyone with information that could be vital to the investigation is encouraged to contact police by phoning 0800 EPOPEUS (0800 376 7387) or email [email protected].

You can also contact Crimestoppers anonymously by phoning 0800 555 111.

Police want to know if anyone saw Shannon Baker's car on Monday night.