Staff at McDonald's Te Ngae took refuge in a safe room and called police after identifying a drive-through customer as potentially dangerous.
Restaurant owner Rob Parry said on Tuesday night a man came to the drive-through speaker and immediately aroused suspicion with the questions he was asking.
"He asked 'are you here by yourself?' which clearly freaked out the person taking the order who said no, there were five or six people on site," Parry said.
"Then they proceeded to the drive-through window and were acting suspiciously. Thankfully we had some senior managers on, who took over the order.
"The person had difficulty swiping their card, they appeared to be under the influence, and they were trying to get us to reach out and do the Eftpos transaction for them."
Parry said the person appeared to be searching for something in the car. Worried that it could be a weapon, the staff decided it was safest to retreat to the safe room and call the police.
A police media spokeswoman confirmed they received a report of a person allegedly behaving suspiciously at the restaurant at 11.01pm.
A person was taken into custody, she said.
Parry said he was pleased with the safety-first approach his staff took.
"They took a super cautious response and I would prefer that every time," he said.
"They made the right call and it's a call I'm thrilled they made."
He said the safe room was designed for armed robberies or any situation in which staff felt threatened.
"It originated from a spate of robberies in Auckland. Every site in the country has got it and it works well in this day in age."
A 51-year-old man was arrested and is expected to appear in Rotorua District Court tomorrow on two drug-related charges.