Police have reclassified a dead body found case as murder after an unidentified woman was found dead outside a flat in Tsuen Wan.

About 12.30am yesterday, Police received a report of a woman found lying outside a flat at 87 Chuen Lung Street.

The woman, in her mid-thirties, was certified dead at the scene. No identity document was found on her.

A post-mortem examination today revealed that she died of suffocation.

The New Territories South Regional Crime Unit is following up the case.