A fatal overdose in an inner city laneway has led to a manslaughter charge against a man alleged to have administered the drug.
Stephen Zachary Quartley, 37, 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 on April 1.
He was treated at the scene by paramedics and taken to hospital in a critical condition.
On April 19 police were informed the man had died.
Following extensive inquiries, investigators executed a search warrant and arrested Quartley.
He was taken to Parramatta Police Station where he was charged with manslaughter, with police alleging he administered the fatal overdose to the older man.
