Hamilton police Sergeant Michael Vaughan said the 30-year-old man was at the Hamilton police station to provide further information about being assaulted.

He suffered a fractured skull late last week and was taken to a Melbourne hospital, treated and then released.

A 19-year-old Hamilton man has been remanded in custody charged with that attack.

While the victim was at the police station, he had a negative interaction with a woman in her 40s who was there to collect personal items.

She was last week charged with trafficking drugs after being caught with 50 grams of ice worth $28,000 as well as drug paraphernalia including vials of urine to beat drug tests.

Police said that the 30-year-old man launched an unprovoked attack on the 41-year-old woman, pulling her hair and threatening to punch her.

The incident unfolded in the police station foyer and outside the station before officers intervened.

The man was charged with unlawful assault and making threats to kill.

He was bailed with strict conditions and is scheduled to appear in the Hamilton Magistrates Court on September 12.