Foreign Affairs Minister Murray McCully says a Labour Party allegation about a conflict of interest involving a government appointee is reckless, cowardly and wrong.
New Zealand's 23% share of the company was sold recently to Singapore company Sofrana.
In Parliament on Wednesday, foreign affairs spokesperson Phil Goff questioned Foreign Affairs Minister Murray McCully about Aucklander Peter Kiely, a director of Pacific Forum Line and lawyer.
Mr Goff asked Mr McCully about his appointment of Mr Kiely to Pacific Forum Line in July 2009 and Mr Kiely's role in Sofrana.
"Was he aware that Mr Kiely was from November 2008 listed under the Companies Register as a shareholder in a competing shipping company, Sofrana, and that he held those shares right through until the 10th August 2012?"
Records from the Companies Office shows that Mr Kiely was a shareholder of Sofrana until August this year.
Mr McCully later released a statement saying Mr Kiely held the shares in Sofrana as a non-beneficial trustee for a Sofrana employee.
He says lawyers commonly hold shares for clients in this way and Mr Kiely was under no obligation to disclose that, as he did not hold personal interests in the company. He says McCully says Mr Goff owes Mr Kiely a fulsome apology.
However, Phil Goff says Government-appointed directors must disclose any relationship or matters that give rise to an actual or potential conflict of interest.