Former NSW Labor MP Ernest Wong has admitted to a corruption inquiry that the effect of some of his dealings was to conceal the true source of tens of thousands of dollars in political donations to the party.

But Mr Wong told the Independent Commission Against Corruption on Wednesday that he did not do so "intentionally".

Former Labor MP Ernest Wong outside ICAC on Wednesday. Credit:Rhett Wyman

The former upper house MP is a central figure in the ICAC's investigation into the source of a $100,000 cash donation to the NSW Labor Party, banked shortly after a Chinese Friends of Labor fundraising dinner for the March 2015 state election.

The ICAC is investigating allegations the true source of the cash was billionaire property developer Huang Xiangmo, who was banned from making political donations in NSW under laws targeting property developers. Mr Huang, who has declined to give evidence, has denied making the donation.