Mr Peters then described the payments as "colossal and unjustified" to media.
Speaking in Parliament last night, Mr Finlayson said the comments were unfair, disgusting, vulgar and crude, and accused him of an "intemperate attack" on the negotiators.
"Mr Peters is nothing more than the Donald Trump of New Zealand politics who wants nothing more than a cheap headline.
"These external negotiators are very good value for money, providing excellent service and are achieving results," Mr Finlayson said.
"I say to New Zealand First that their tendency to personalise things and attack the individuals as they have done with my treaty negotiators is something I resent and something I think is quite simply disgusting.
"These people are good people and I am very proud of the work they are doing regardless of party or regardless of background."
Mr Finlayson said John Wood, chancellor at Canterbury University, had done "phenomenally well" in two difficult treaty negotiations: Tuhoe and the Whanganui River.
Mr Peters lashed out himself saying Mr Finlayson needed to "get a grip and stop reverting to hissy fits every time some truth is told about his organisational spending".
"Reverting to diversions and straw men in some vain attempt to avert attention from gross expenditure items to individual treaty settlement negotiators simply won't do," Mr Peters said.
"It is clear that a number of negotiators were reasonable in their charges and no one is challenging them, and nor did I."
However one negotiator received more than $2.26 million over seven years and another $1.55 million.
"The public will want to know just what sort of complexity justifies those extraordinary costs and Mr Finlayson needs to know that puerile attacks on me are going to have no effect at all."
