A Labour MP says Chinese workers for KiwiRail are too afraid to tell the truth about how poorly they're being paid.

The Ministry of Business Industry and Employment has been accused of covering up poor working conditions for Chinese workers in Lower Hutt.

MBIE has released the results of an investigation into allegations from Lower Hutt and Labour MP Trevor Mallard Chinese working for Kiwirail were being paid poorly, and living in terrible conditions.

Mallard believes workers are afraid to be honest.

"The Chinese companies don't want to be forthright about their employment conditions because it will be very embarrassing for them and they will never get contracts within New Zealand again."

The Labour MP says workers refused to tell investigators what their wages were, as did Chinese company supplying them. 

"There's a requirement in New Zealand for people to comply with minimum codes of employment while here. These people are clearly not doing that and I'm surprised that the Ministry's covering it up."

Mallard says legal advice he's received suggests the ministry is wrong in its interpretation of New Zealand law.