"I am confident that our decision to withhold some information was the correct response. We will cooperate fully with any approach the Ombudsman makes as a result of your referral."
The Herald first asked for Liu's residency file on May 8 and the Immigration Minister Michael Woodhouse asked for information on the file the next day.
Immigration officials refused the request on Monday, on privacy grounds, so a refined request was made for any correspondence from MPs leading up to Liu's residency bid being granted against advice in 2005.
Two days later, the 2003 letter from Mr Cunliffe to Immigration officials was released and published online by the Herald - despite the Labour leader earlier denying he played any party in Liu's residency.
He has since been battling to save his job and has since accused the National Party of a dirty tricks campaign in the lead-up to the election.
Prime Minister John Key had earlier admitted knowing about the letter from Cunliffe for several weeks after being briefed by Mr Woodhouse's office, but denied it was a smear campaign.
Minister's account
May 8: Immigration Minister Michael Woodhouse is questioned in the House and by media about his meetings and any National Party association with Donghua Liu. Mr Woodhouse requests information on the file to see if there is anything relevant that he needs to know about. The Herald requests Liu's residency file under the Official Information Act (OIA).
May 9: In response to file review, Mr Woodhouse is verbally advised - among other things - of the existence of two Parliamentary advocacy letters regarding Donghua Liu, one from Mr Cunliffe and another from the office of Chris Carter.
Weekend of 10-11 May: Mr Woodhouse informs Prime Minister John Key's Office of the existence of the letters.
Week 12-16 May: Mr Woodhouse's office receives hard copy of letters.
Mid-late May: Mr Woodhouse's office provides copy of letters to the Prime Minister's office.
June 16: The Herald run story on Labour donations and connections. The Herald's OIA request is declined on privacy grounds. The Herald puts in a refined OIA request for MP representations for Donghua Liu to Immigration NZ.
June 18: Immigration NZ release Mr Cunliffe's Donghua Liu letter to the Herald.
June 19:
• 2pm Mr Woodhouse denies telling Mr Key about the letters
• 3pm Mr Woodhouse says officials from his office briefed Mr Key's office on the letters.
• 7pm Mr Woodhouse's office says the minister himself told Mr Key's office about the letters and his office also gave copies of the letters to Mr Key's office.