"Did you ever get a thank-you note or a thank-you call?"Mr Watson asked.

"Yes I did. I thought it was a call,"Mr Di Girolamo said.

The commission is investigating allegations that the Obeid family were"secret stakeholders"in Australian Water and stood to make up to $60 million from a proposed public-private partnership.

The month following the bottle of Grange being couriered to Mr O'Farrell's northern suburbs home,Mr Di Girolamo attended a meeting with the Premier on May 27,2011 to lobby him about the proposal.

Former water minister Greg Pearce has given evidence of being summonsed to this meeting and that he was annoyed to find that Mr Di Girolamo had gone behind his back to lobby the Premier directly.

Mr Pearce said he felt like a schoolboy being called to the headmaster's office for not doing his homework.

"I was quite taken aback that it seemed to be so cosy,"he said of the meeting.

Mr Watson accused Mr Di Girolamo of"trying to butter Mr O'Farrell up",a suggestion Mr Di Girolamo denied.

"I didn't need to buy my access to the Liberal Party,"he said.

"Wasn't it an attempt to grease the wheels?"Mr Watson said.

"No,"Mr Di Girolamo replied.

The inquiry has heard Australian Water became one of the biggest donors to the NSW Liberal Party in the months before the state election.

Mr O'Farrell's meeting with Mr Di Girolamo occurred six days after the latter emailed the then chairman of Australian Water,Liberal President Arthur Sinodinos,asking him to"ring BOF".

Senator Sinodinos told ICAC he did not make the call.

Mr Di Girolamo also said that he thought Mr Sinodinos would have known of the donations to the Liberal Party because of"his position on the board."

However,he could not recall specifically whether the donations were discussed at board meetings.

The Premier is due to give evidence at the inquiry later on Tuesday.

The inquiry continues.