Police are investigating a homicide in Auckland’s Mt Wellington after a man was found dead outside a business.

The man was found dead in a car on Penrose Rd after police responded to reports of gunshots being heard about 10.40pm.

Police tape surrounds a car park outside a number of businesses, including a vape store, dairy, superette and roast shop.

“Police have been in the area overnight speaking to a number of witnesses who were in the vicinity at the time of the incident,” Detective Senior Sergeant Ash Matthews said.

“While it is early in the investigation, there are indications that the parties involved were known to one another.”

A car with a smashed window on the driver’s side can be seen within the police cordon.

A car with a smashed window at the driver's seat can be seen within the police cordon at the scene of a homicide in Auckland's Mt Wellington overnight. Photo / Isaac Davison

A shop owner near the scene said he and his partner closed their store at 10.30pm and headed to bed.

Around 10 minutes later they heard loud voices on the street and then a sound “like a firecracker”.

They did not realise anything had happened until this morning, when police officers stopped them from opening their shop.

The people on the street appeared to be arguing, said the shop owner, who declined to give his name.

“There were two of the firecracker sounds - so that must have been two [gun]shots.

”We had no idea,” he added. “There is not usually much trouble here.”

A scene guard is in place and Mt Wellington residents can expect an increased police presence in the community.

A post-mortem examination and formal identification of the victim will be carried out over the coming days.

Police are encouraging anyone else who was in the area or has information to assist who has not yet spoken to police to get in touch by calling 105 and quoting file number 240714/0428.