A Malaysian people smuggler passing through New Zealand has been caught and sent home.

Customs officials in Auckland Airport stopped three men travelling on fake Malaysian passports after noticing their unusual accents, TVNZ reports.

Under questioning, the trio revealed they had paid the Malaysian man a large sum of money to smuggle them into South America.

Their genuine Chinese passports were discovered in their luggage.

The three were sent back to China, while the people-smuggler was also sent back to Malaysia.

He could not be charged as he was not attempting to enter New Zealand, but he was expected to face charges in Malaysia.

Immigration New Zealand border operations manager Karen Urwin says the group appeared to be surprised at first.

"We were suspicious enough that we decided we'd go and talk to them," she says.

"They'd already been denied entry into Argentina and I don't think they were expecting to be interacted with by Immigration New Zealand. I think they just thought they would go home and try their luck next time around."

Ms Urwin was "pretty sure" the Malaysian man would face charges when he arrived home.

"We do know from interviewing him that he's part of a much larger professional smuggling ring operating out of Malaysia.