A Waikato police officer put others ahead of himself when he drove in front of a driver suffering seizures to prevent him crashing into other vehicles.

A spokesperson for police said the possibility of someone being killed during the incident was high.

But the Te Awamutu sergeant's actions meant the seizuring driver was stopped from crashing into oncoming motorists on a Waikato road, Fairfax Media reported.

The sergeant was not injured during the incident.

Around midday on Monday the officer saw a vehicle crossing the centre line of Paterangi Rd.

Waikato police Senior Sergeant Simon Cherry said the car was doing 60km/h in a 100km/h zone.

The sergeant tried to pull the vehicle over by flashing lights and activating his siren, but the driver did not halt on his path.

"So he pulled in front of the car, as it was a real danger and was travelling into the other lane in a 100km/h zone.

"But the car just kept going and collided with the police car," Cherry said.

The driver, a 62-year-old man, was having seizures behind the wheel.

Cherry credited the officer's actions in preventing a serious crash, Fairfax reported.

"This could easily have been a fatality.

"Ultimately the officer prevented a fatality and saved someone's life, and got medical assistance for someone who is not very well and shouldn't be driving."

The driver had a medical assessment and police were continuing investigations.