Three-car crash at Hampton Downs Motorsport Park, Waikato

The Auckland Westpac Rescue Helicopter at the scene of the three-car crash, on the race track at Hampton Downs. Supplied photo / Auckland Rescue Helicopter Trust

A man aged in his 50s has been seriously injured after three cars crashed on the race track at Hampton Downs Motorsport Park this afternoon.

A police spokeswoman said the drivers of the two other cars involved in the 2.15pm crash at the North Waikato motorsport venue had moderate and minor injuries respectively.

Auckland Westpac Rescue Helicopter airlifted the worst injured driver to Auckland City Hospital.

The drivers of the three vehicles were the only occupants.

Auckland Rescue Helicopter Trust communications' manager Lincoln Davies said the seriously injured man was initially trapped in his vehicle and needed to be freed by the fire service.

"He suffered multiple injuries and was flown to Auckland City Hospital in a serious condition."

The police spokeswoman said paramedics were at the race track at the time of the crash. St John also sent an ambulance from Hamilton, but couldn't be contacted by the Herald.

In a tweet St John said one of the patients was taken to Middlemore Hospital.

WorkSafe had been told about the crash, the spokeswoman said.