When he was prime minister, Kevin Rudd and his senior ministers held fake pre-budget meetings as a precaution against the possibility of plans being leaked by Lindsay Tanner.
The Sydney Morning Herald reports some meetings with the then-finance minister would deliberately be light on detail because others in the so called "gang of four" were so suspicious of him.
After the meeting ended, the Strategic Priorities and Budget Committee's other three members - Mr Rudd, Julia Gillard and Wayne Swan - would reconvene and discuss their plans in detail.
Departmental sources said the tactic was motivated by a suspicion internally that Mr Tanner was behind the leaking of budget stories early in the first term of the Rudd government.
But there has been no evidence Mr Tanner ever leaked anything, the Herald reported on Tuesday.
Mr Tanner retired from politics at the last election.