Maritime NZ says it strongly rejects allegations it took action against a business after its managing director told a Parliamentary select committee the agency was "grossly overcharging".

Speaker David Carter received a letter from Labour MP David Cunliffe raising concerns about Maritime NZ's actions against Margaret Wind, managing director of Maritime Management Services Ltd.

Those alleged and unspecified actions came after Wind made a submission to the Regulations Review Committee that was strongly critical of Maritime NZ.

"It is suggested that this action could amount to a contempt of the House in that the managing director may have been disadvantaged on account of giving that evidence," Mr Carter said this afternoon.


"An allegation that a state sector agency used its power against a person on account of evidence given to a select committee requires serious attention, given the importance of free speech to this House."

Mr Carter said he had referred the matter to the Privileges Committee to investigate.

Because of that action, Mr Cunliffe said he was unable to provide details, including on what actions Maritime NZ was alleged to have taken against Wind.

A spokesman for Maritime NZ issued a one line statement, saying the organisation, "strongly rejects the allegations made and will fully cooperate with the Privileges Committee inquiry".

Maritime Management Services has been contacted for comment.

In her April 27 written submission to the select committee, Wind said Maritime NZ had failed the sector by "grossly overcharging".

"Maritime NZ's aggressive approach and abuse of privilege has led to a reduction of an estimated 20 per cent of domestic operators - and an over 60 per cent reduction in surveyors within eight months," Wind wrote.

Parliamentary Practice in New Zealand states that the House is concerned to "protect witnesses against any adverse consequences being visited on them as a result of their giving evidence to the House or a committee".