"A 19-year-old woman was found lying face up in the water while a 41-year-old man was found underneath her, trying to avoid detection by police," he said.
Firefighters and paramedics attended to the pair, who were then taken to Waikato Hospital.
The Hamilton Police rescue boat and a Waikato River Harbour Master vessel searched for the missing man.
Mr O'Reilly said with the aid of a thermal camera provided by firefighters a 29-year-old man was found hiding in the river clinging to the bank about two hours after fleeing from the crash scene.
"We believe this person, who was wanted on a parole recall warrant, was the driver of the car, he was pretty relieved to be pulled out of the water even though he faced arrest.
"He was taken to Waikato Hospital for treatment for hypothermia," Mr O'Reilly said.
"The 41-year-old gang member found hiding under the woman was wanted on a warrant to arrest for outstanding fines and the $1,200 cash he had on him when arrested has been forfeited to the courts," Mr O'Reilly said. "Police enquiries today will focus on a quantity of what is believed to be methamphetamine recovered from the car."
The incident comes almost two months after a car plunged into the Waikato River after colliding with the Pukete Bridge on June 6. Eunki Kim, 40, remains missing after the crash.
"Given we still have a woman outstanding after eight weeks when her car crashed into the Waikato River it's pretty disappointing someone will risk their own safety and the lives of others by jumping in the water in a vain attempt to avoid arrest."
- Herald Online