Car in harbour after ploughing 'slow down' sign

They managed to walk to a nearby house and alert emergency services. Photo / Supplied

Two men had a "lucky escape" after the vehicle they were in ploughed through a "Slow down before bends!" sign and went into Otago Harbour.

The pair were taken to Dunedin Hospital after the crash near Sawyers Bay about 1.30am yesterday.

Station officer Glenn Holland, of Port Chalmers, said the pair were "very lucky" after the vehicle plunged into the cold and dark waters.

"They are very lucky lads," he said.

"They will be thanking their stars today, I'd imagine.

"They had to have a swim. They were very lucky to get themselves out of the car.

"It would have been very frightening for them."

St John South Island region communications adviser Ian Henderson said it was unclear what injuries, if any, the pair sustained as a result of the crash.

They managed to walk to a nearby house and alert emergency services.

The car had crossed the centre line, smashed through the sign and rolled into the harbour.

Senior Sergeant James Ure said police were investigating the circumstances of the crash and inquiries were ongoing.