Seven West Media chairman Kerry Stokes is understood to have threatened to resign from the Australian War Memorial Council in anger at Australian Federal Police raids on the Seven network.
Stokes, who joined the council in 2007 and was re-appointed to another term in 2011, has been one of the War Memorial's most generous donors.
Stokes has purchased and donated four Victoria Cross medals, worth around $600,000 each, to the memorial.
In 2012 he donated over 800 glass-plate negatives depicting Australian soldiers in World War I.
Sources said Mr Stokes' departure would come as a blow for the War Memorial as it prepares to commemorate the centenary of Anzac Day next year.
Fairfax Media asked Veterans' Affairs Minister Michael Ronaldson this morning whether Mr Stokes had resigned from the council.
A spokesman for Mr Ronaldson responded: “The Minister has responsibility for a number of Boards, including the Australian War Memorial Council, and does not discuss conversations between himself and members of those organisations.”
A Seven spokesman said Mr Stokes was currently travelling overseas.