Cameron's top 20 backers gave the cash over a three-month spell this summer, after invites to swish events with the Prime Minister, the Sun reported, quoting Conservative Party figures.
Each benefactor is part of the elite "Leader's Group", which entitles them to attend dinner with the Prime Minister and senior figures, lunch after Commons questions and VIP receptions. There is a 50,000 pound joining fee.
The biggest donor was City financier Michael Farmer who gave 525,000 pounds between July and September, having previously handed over 2.5 million pounds. Chancellor of the Exchequer George Osborne also attended the suppers, the report said.
Cameron, 46, apologised earlier this year after a fundraiser quit for bragging a big donation could get dinner with the Prime Minister.
The Leader's Group events are all within the rules, the report said.
But Labour vice-chair Michael Dugher slammed Cameron, saying: "It's the same old cash for access."
