Manslaughter charge laid over laneway drug overdose

A fatal overdose in an inner city laneway has led to a manslaughter charge against a man alleged to have administered the drug.

The 37-year-old was arrested at an address in Parramatta on Thursday following a months-long police investigation.

It comes after emergency services found a 45-year-old man unconscious in Parker Lane in Sydney's Haymarket around 5.20pm on April 1.

He was treated at the scene by paramedics and taken to hospital in a critical condition. More than two weeks later on April 19, police were informed the man had died.

Following extensive inquiries, investigators executed a search warrant and arrested the 37-year-old.

Police will allege in court that he administered the fatal overdose.

The man was taken to Parramatta Police Station where he was charged with manslaughter.

He is due to appear in Parramatta Local Court on Friday.