Hamilton Police have begun a search for a missing person in the Waikato River

Emergency services were alerted to a person going missing in the river in the Hamilton Gardens area about 9.45 last night.

A second person went into the river to try to save them, but couldn't reach them.

That person had to be taken to Waikato Hospital for medical treatment.

A police boat is being used to search the river and the river bank this morning.