New Zealand First is seeking assurances a corrupt Chinese tax official who previously fled to New Zealand won't be allowed to return.

Yun Jian has been given a suspended sentence and a fine equivalent to $40,000 for taking almost $124,000 in bribes.

He surrendered himself and returned to China in July last year.

New Zealand First leader Winston Peters says he should never been allowed to come to New Zealand, and there's no reason he should be allowed to return.

"He's on the Chinese 100 most wanted list, he's been back to China to be charged - I don't see how he could come back to New Zealand now on a good character test."

Mr Peters believes this is a sign our immigration settings need to be changed.

"Somebody should be asking the Ministers how did this man get here in the first place [and] what checks did they make in mainland China? Because, had they made them, he wouldn't have made it in the first place."