Police believe a man who leaped from a moving car in Hamilton yesterday before disappearing into the Waikato River is likely to have drowned.

The man was being pursued by police after being seen leaving the scene of a burglary in Glenview about 9.45am.

Waikato police spokeswoman Kris McGehan said police were responding to a reported burglary when they saw a car that had been described by the alleged victim speeding along the road.

The police car stopped in the middle of the road and indicated the driver to stop but he drove around the police car and sped away.

Ms McGehan said the police car turned and followed but the driver they were chasing abandoned the car while it was still moving. The car stopped about 100m down the road.

The police chased the driver through the grounds of the Glenview Club before he leaped a fence, jumped into the river and swam a short distance out.

Ms McGehan said the man then turned and swam back towards the shore, stopping to rest on a rock in the water, but let go and drifted downstream when two officers prepared to go in and get him.

The man was reported to have been bobbing up and down, gasping for breath, before disappearing from sight.

The officers continued searching the water but were unable to find him. Searches using a helicopter, boat and people scouring the riverbank were also unsuccessful.

Ms McGehan said police believe the man drowned and are trying to identify him with the help of the owner of the home which was burgled.

She said a police dive squad from Wellington might be called in to search the river today.