Mr Banks last night released a hotel invoice to attack claims he got a discount at the Grand Hyatt Hong Kong. The invoice showed a room rate about half of the current quoted cost.
The invoice came from a Christmas holiday taken by Mr Banks, who just two weeks before had been sworn in as a minister, and his wife Amanda.
Last night, Mr Banks' staff insisted there was no discount attached to the hotel stay. A spokeswoman said she was present when Mr Banks sought and received an assurance there was no discount attached to his bill.
She said Mr Banks asked specifically if there was any discount applied to his bill and was told by the hotel manager there was not.
But Mr Banks today said: "I negotiated the price for the hotel room and I paid for everything in Hong Kong.
"I always negotiate prices down, I don't believe in paying the rack rate in a hotel."
"The hotel room was so expensive I even paid for it with my wife's credit card."
Mr Banks this afternoon said his association with Dotcom was not the reason he was able to negotiate a lower charge for the room.
The invoice Mr Banks produced last night showed he and his wife were charged $678 a night.
Staff at the hotel's reservations desk last night said the rate for the room the Banks stayed in was $1303, including a 10 per cent service charge.
Mr Banks has faced questions over his relationship with the internet tycoon - currently facing an extradition hearing on charges of criminal copyright violation - after it emerged that his failed 2010 Super City mayoral campaign got $50,000 from him.
The questions intensified after claims by Dotcom that Mr Banks asked him to split the donation into two lots of $25,000 so they could be made anonymously.
And Mr Banks faced further challenge after it emerged he had lobbied a government minister on Dotcom's application to buy property.
Opposition MPs have called for Prime Minister John Key to stand down Mr Banks as a minister while police investigate complaints over donations to Mr Banks.
Labour's Trevor Mallard made the claims about Mr Banks' Hong Kong hotel accommodation in Parliament yesterday, saying Dotcom had helped arrange it.
This afternoon Mr Mallard was to ask Mr Key further questions about Mr Banks' mayoral campaign finances, this time centred on donations for radio advertising.
The Banks' holiday trip was revealed by the Weekend Herald, which detailed how Mr Banks had telephoned Dotcom's bodyguard to ask for a hotel recommendation.
Dotcom, who has rented the top floor of the Grand Hyatt for seven years, suggested Mr Banks stay at the hotel and helped to make arrangements for the holiday.
Mr and Mrs Banks were collected by limo from the airport, taken to the hotel and later used the limo to travel to the ferry terminal for a trip to Macau.
Late last night, the minister's office sent the Herald a receipt showing that Mr Banks paid for the limo himself.
Earlier yesterday, Mr Mallard asked if Mr Banks had told the Prime Minister or his office that "Mr Dotcom facilitated a discount for personal accommodation for Mr Banks at the Hyatt in Hong Kong while Mr Banks was a minister?"
"If so, did he or his office ensure that Mr Banks was properly briefed on the requirement to declare that discount on his Declaration of Pecuniary Interests?"
Mr Key said Mr Banks had not, to the best of his knowledge, told him about discounted accommodation "but my chief of staff has said to me that Mr Banks has made an assurance that he paid for all expenses on the trip to Hong Kong".
Mr Key also said he had still not spoken directly with Mr Banks about the matter. "I don't need to. I've had a cast-iron assurance from him that he complied with the Local Electoral Act and that's good enough for me."
Under Parliament's rules, MPs must declare any gifts with a value of over $500. Any gifts over $500 received in December should be in the next Register of Pecuniary Interests, which should be released this month.
Mr Banks would have the opportunity to amend the declaration, if it emerges there was a discount and if it was decided it should be declared.
- By David Fisher and Adam Bennett of the New Zealand Herald
