Police are searching for a man following a reported indecent assault in Auckland yesterday.

A police spokesman said police are making inquiries into a reported indecent assault in Silverdale about 10.30pm.

"A woman reported being approached by a male in the motorway underpass," the spokesman said.

"As we are in the early stages of making inquiries into this incident, we are unable to provide any further detail."

Any members of the public who were in the area at the time and witnessed any suspicious activity are asked to contact Orewa Police Station on 09 426 4555.