Police and Search and Rescue teams are at Manuka Bay in Domett, Hurunui, where a diver is missing.
A police spokesperson said the person was one of two people diving at the bay, in water about 5 metres deep.
Police were called about 2.15pm.
A helicopter has assisted with search efforts, however, there has been no sign of the missing person.
The Police Dive Squad has been alerted and is expected to join the search in the morning.
Support is being provided to the diver’s family the spokesperson said.