A senior staff member for a Labour MP wrote a letter on behalf of wealthy businessman Donghua Liu's residency application because he had invested $3 million.
Documents released under the Official Information Act show an electorate agent for Chris Carter, wrote to Immigration officials asking "for any consideration that could be given to expediting" Liu's bid to live permanently in New Zealand.
The letter was sent in October 2002 on an official letterhead from Mr Carter's office, who was the MP for Te Atatu at the time.
The agent wrote wrote that she had been approached by a local constituent, Hui Lee, who was in business with Liu.
Mr Lee's company had made an offer on a property in central Auckland for development purposes.