Sinodinos' frontbench return revisits ICAC

Cabinet Secretary Arthur Sinodinos is confident he won't be found to be involved in corruption, based on his "encyclopedic knowledge" of proceedings.

The newly-returned frontbencher resigned as assistant treasurer under the Abbott government after his conduct came into question during hearings of the NSW Independent Commission Against Corruption.

The questions relate to donations made to the Liberal Party by Australian Water Holdings, of which he was deputy chairman.

Senator Sinodinos was promoted back to minister after Malcolm Turnbull ousted former prime minister Tony Abbott and reshuffled the cabinet last month.

When pressed on his first day in parliament in his new role, Senator Sinodinos said the ICAC report would be a "fascinating document".

Opposition Senate leader Penny Wong asked him if he had given an assurance to the prime minister similar to a public statement saying he was confident there would be no adverse findings against him.

"What I have said to the prime minister privately is what I have said publicly," he told the upper house on Monday.

And on what basis was that assurance given?

"On an encyclopedic knowledge of proceedings," Senator Sinodinos said.

Senator Sinodinos was greeted with heckles from the opposition during his first question on Monday, many of who yelled out "welcome back".