A homicide investigation has been launched after a man died at a party in Hastings overnight.

The 39-year-old died at a Flaxmere address early this morning, police said.

A 25-year-old man was arrested at the scene and was assisting police with their inquiries.

He would appear in Hastings District Court tomorrow charged with assault.

Police were still attempting to establish what happened and would not comment further.

A post mortem would be carried out tomorrow.

- NZPA