Labour has denied it's pulling the race card by calling for an investigation into the passing of six cheating Saudi Arabian Unitec students.

An engineering lecturer reportedly resigned in protest after six students from the country were allowed to pass, despite cheating in their final test. The tertiary education union claims there is too much pressure to pass high-paying international pupils.

Unitec says the students were treated the same as any other Kiwi students would have been in the same situation, but Labour education spokesperson Chris Hipkins isn't buying that.

"If they are handling the situation the same as they would handle any other case, then I've got concerns about their processes because students who are caught cheating shouldn't be allowed to get away with that."