Police officers were doused in a decontamination shower after finding bags of chemicals in a crashed car in Hamilton's Melva St.
Dinsdale resident Bill White said officers handcuffed and arrested the male driver of the car about 8.30am on Saturday before calling in the fire service to wash down the scene.
White said it appeared the driver was travelling along Bremworth Ave at high speed before he lost control and hit a give-way sign and a small roadside tree.
"The driver didn't look injured but police had him sitting on the curb with his hands cuffed as they pulled out two big bags from the back seat of his car," he said.
"Later two fire trucks arrived and they used soapy water to hose down the road and grass and tree."
White said Melva St was blocked off for about three hours as officers examined the car.
Fire northern communications shift manager Steve Smith confirmed the fire service's decontamination unit was called to the scene after unidentified chemicals were found in the crashed car.
The scene, as well as people, were washed down while the contaminants were put into drums for safety.
Meanwhile, a young woman is in Waikato Hospital with critical injuries after a drink-driver crashed into a tree early yesterday.
The 21-year-old woman was a passenger in the single-vehicle crash in Garden Heights Ave, Melville about 3.30am, police said.
The Mercedes Benz hit a tree then bounced into a power pole, snapping it, Acting Senior Sergeant Lara Beisly said.
The driver was found at the scene and was clearly intoxicated.
Speed was also a factor in the crash, she said.
Police said it was another example that alcohol and driving do not mix.
And traffic was diverted away from Hamilton's Pembroke St after a car crashed into a traffic lights pole yesterday morning.
Hamilton police Senior Sergeant Gael Mockford said the driver was in hospital with critical injuries.
Pembroke St resident Dilip Kurien said he was getting ready for church when he heard the crash which happened about 5am.
He went outside to find a "very young woman" standing by the car.
"I couldn't see if anyone else was in the car only the woman standing by it trying frantically to phone someone," Kurien said.
"I'm not sure why she crashed.
"It's a nice stretch of road, it wasn't foggy and there wasn't any other traffic," he said.
"The car was facing in the wrong direction and the traffic lights were lying on the ground."
The police Serious Crash Unit is investigating the crashes.
- Waikato Times