While an Act MP in 2012, Mr Banks had to declare a $1000 gift basket from Mr Dotcom while he was on holiday in Hong Kong, but said he had given the gift basket away.
Mr Thompson said Mr Cunliffe's claim was spurious.
"What happened to Mr Cunliffe's 'Vote Positive' campaign? NO money from Dotcom has ever been donated to an ACT campaign," Mr Thompson said.
Mr Cunliffe said he had spoken to Mr Davis about his campaign.
"I've said to him that I expect all candidates to reflect the general tenor of our campaign messages, which are positive ones.
"Of course we are backing him to win in a vigorous campaign up north - he's a good candidate and he's certainly on board with our overall direction."
Mr Davis' Facebook post prompted National-aligned bloggers David Farrar and Cameron Slater to donate about $100 each toward his campaign.
Mr Davis said he would forward the money to Rape Crisis rather than accept it for himself, and thanked the two men for their contribution to his campaign against sexual violence.
The Facebook entry followed a decision by Labour's head office to veto a proposed fundraising website for Mr Davis partly because it was critical of Internet-Mana.
Kelvin Davis.
On Firstline this morning, Mr Cunliffe again ruled out a forming a government with Internet-Mana - but did not rule out offers of support.
"I've said they won't serve as part of a government that I lead. That does not preclude them from offering their support from outside of government. That is a matter for them, not for me."
- APNZ and Claire Trevett of the New Zealand Herald