A man who attempted to swim across the Waikato River last night is presumed drowned, according to police.
The 22-year-old was attempting to swim across the river near Jellicoe Drive when he disappeared shortly before 9pm, police said.
He is presumed to have drowned after family saw him slip below the surface while another man was attempting to rescue him.
Indications were that the young man was not a strong swimmer, police said.
Police and the fire service last night conducted land searches of the east and west banks of the river, during which thermal imaging equipment was used from a boat in case the missing man was on the rivers edge exhausted or unconscious.
Water and land based searches continued in to the early hours of the morning and resumed at first light.
It was devastating for the family who were enjoying some recreation time at the river, and a tragic reminder of the Waikato River's strong current and many snags below the surface, police said.
Swimmers needed to ensure they did not venture in to activities outside their capabilities.
The Waikato River was sacred to Iwi, who had been advised of the tragedy.