All claims of fraud and bullying inside Australia's largest transport project will be investigated but the public might have to wait to know the result.
NSW Transport Minister Jo Haylen on Monday confirmed she had ordered additional oversight measures for Sydney Metro amid several allegations of improper behaviour at the agency building three key routes at a cost of at least $55 billion.
It followed her request last week that Metro appoint an independent legal expert to investigate concerns over the use of contractors and improve probity.
"All of those instances will be investigated," Ms Haylen told reporters on Monday.
"In relation to any instance of alleged corruption, the CEO of Sydney Metro (Peter Regan) has a positive duty to report any instance."
Some of the allegations - historical cases of Metro contractors hiring staff from their own companies into positions within Metro - mean Mr Regan is now required to approve all contracts worth more than $250,000.
Sydney Metro said the corruption watchdog, ICAC, had been notified of the internal investigations and findings.
"Sydney Metro is not aware of ICAC having conducted any investigations resulting in findings by it of corruption by Sydney Metro's workforce," a spokeswoman said.
Premier Chris Minns said he appreciated taxpayers had an interest in knowing their money was being spent properly but each investigation needed to run its course without being compromised by being aired publicly.
"Of course, we'll communicate with the people of NSW as soon as we have information," Mr Minns told reporters on Monday
The NSW government is preparing to reveal its plans to add new stations to the Sydney West Metro to help offset budget blowouts.
Additional stations would slow the commute between the Parramatta and Sydney CBDs but would open more options for high-density housing.
Ms Haylen on Monday faced further questions about her knowledge of a public servant's political work inside her ministerial office.
Documents to parliament show the staffer, who Ms Haylen knew through Labor circles, was involved in writing op-eds and engaging with stakeholders.
But Ms Haylen said it was clear the preparation of policies, speeches, media releases and op-eds were included in the role of a department liaison officer.
"It's not a breach in the specifics here because it's very clear the communication of government policy is included within the role," she told reporters.
The premier dismissed concerns about the scandal around the staffer's work by pointing to the "massive" number of former coalition ministerial staff working in senior government positions.
"It's scores of staff," he said.
"I'm not coming here saying they should all be sacked ... in many cases, we work with them on a daily basis."
The opposition claims the staffer's appointment, requested by Ms Haylen's former chief of staff, is a clear case of "jobs for the boys", a charge denied by the government.
