The police dive squad is expected to arrive in Taupo at lunchtime today to carry out a search for reports of a man disappearing while swimming in the Waikato River last night.
Police were told just before 9pm a man in the natural hot pools at Spa Park had swum into the main flow of the Waikato River, but did not get back to the river bank.
Senior Constable Barry Shepherd, of Taupo, said police, the Greenlea Rescue Helicopter, Coastguard Lake Taupo and Land Search and Rescue Taupo volunteers searched for the man last night but were unsuccessful and ended the search about 1am.
The police national dive squad will arrive to help today.
The identity of the missing man is not known, Mr Shepherd said.
"Police would be grateful for any information from anyone who could help to identify him.
Police have received credible information from other swimmers at the hot pool who witnessed his disappearance about 200 metres downstream.
"However if this person has swum successfully from Spa Park to Reids Farm, police are pleading for him to call."
Anyone with information should call 111 and ask for police, he said.
The natural hot pool at Spa Park is where the Otumuheke Stream flows into the Waikato River, and is a popular attraction. About 20 were at the pools when the man disappeared.