A 57-year-old man has been arrested and charged by Serious Crime Squad police for allegedly assaulting a man in a Mitchell Street establishment a year ago, NT Police said.

On January 30, 2021, the man allegedly attacked a 48-year-old man in the pub in an unprovoked attack.

Police said the victim had sustained serious factures to his back and a mild concussion as a result of the alleged assault.

Police did not say if the offender was intoxicated when he attacked the victim or if both men were drunk.

Nearly a year after the incident, NT Police said the victim lodged a formal complaint this month at the Darwin Police Station.

Details as to why the victim only filed a complaint a year later were not provided by the police media unit.

Authorities investigated the complaint and located and arrested the 57-year-old man on Friday.

Police say they took the man to Palmerston Watch House where he was charged with one count of unlawfully causing serious harm.

He is scheduled to appear before the Darwin Local Court on February 10, 2022.