The masked duo arrived at Heritage Court Motor Lodge on Thames Hwy around 10pm on Thursday last week and began looking through windows, Sergeant Blair Corlet said.
A witness from Christchurch who was staying at the lodge confronted the two men.
He was then assaulted and the pair allegedly stole his backpack which contained his cellphone and thousands of dollars of cash.
A 24-year-old Oamaru man was arrested in relation to the incident three days later and appeared in the Dunedin District Court the next morning facing a charge of aggravated robbery.
He was remanded in custody and will apply for bail tomorrow.
Police earlier said inquiries were ongoing to apprehend the second man but yesterday, a 21-year-old was also before the court.
His counsel John Westgate said there would be no application for bail and the case was transferred to the Oamaru District Court to be heard in April.
Judge Emma Smith granted interim name suppression, which would be revisited at the next appearance.
Police recovered all the stolen goods that were stashed at an Oamaru address and returned to the victim, Sgt Corlet said.
