The family of disgraced former Labor powerbroker Eddie Obeid wanted their $3 million stake in a water infrastructure company kept quiet, a NSW corruption inquiry has been told.

Obeid’s family bought a 30 per cent stake in Australian Water Holdings (AWH), the second day of the Independent Commission Against Corruption’s (Icac) Operation Credo inquiry heard on Tuesday.

“I understood that they [the Obeids] did not want it publicised for a period of time,” AWH shareholder John Rippon told the hearing.

“I understood that because they had a name that was out there all the time they did not want it publicised where they were.”

After buying the shares, it’s alleged Obeid lobbied fellow Labor NSW ministers to approve a multimillion dollar business contract between the state government and AWH.

The deal, if approved, would have benefited AWH’s shareholders and directors, including current federal assistant treasurer Arthur Sinodinos, to the tune of hundreds of millions of dollars.

Sinodinos, whose role as a witness in the inquiry has put his job under intense scrutiny, stood to pocket a bonus worth up to $20 million if the deal proceeded, the Icac has been told.

He was employed as an AWH director from 2008, with an alleged remit to open doors to the Liberal party.

The then Labor water minister, Joe Tripodi, is accused of doctoring a cabinet minute to try and have AWH’s proposal to supply water infrastructure in Sydney’s north-west approved by the state government.

Another former Labor minister, Tony Kelly, and his chief of staff are alleged to have also altered or at least approved the cabinet minute.

Ultimately the deal, which would have increased AWH’s value by about $200 million over six years, was knocked back by the NSW government.

Liberal party fundraiser Nicholas Di Girolamo sold the Obeid family the AWH shares, Rippon told the Icac.

Girolamo and Rippon both owned shares in a racehorse called “Partner in Crime”, the inquiry heard.

Di Girolamo was former Liberal opposition leader John Brogden’s chief fundraiser and was employed as AWH’s chief executive in a bid to open doors to senior Liberal ministers, Rippon said.

He was also close friends with the Obeid family.

Counsel assisting the Icac inquiry, Geoffrey Watson, said Di Girolamo was paid a $250,000 signing-on fee when he joined AWH, a $750,000 salary and a minimum $250,000 bonus.