A man arrested on suspicion of killing a number of women and dumping their bodies in an old quarry escaped from police custody in the Kenyan capital Nairobi on Tuesday, police said.

Collins Jumaisi was arrested last month in connection with the discovery of at least six bodies wrapped in plastic bags in Kware quarry, which is now used as a rubbish dump.

He broke out of the Gigiri police station alongside 12 Eritrean nationals, police spokesperson Resila Onyango said.

Police say Jumaisi admitted to killing 42 women including his wife, but his lawyer told a court he was tortured into making a confession. Prosecutors deny he had been mistreated.