Prime Minister Tony Abbott has been drawn into a row over the role a senior ministerial staffer played in the taking down of a food ratings website.
Mr Abbott fended off questions from Labor frontbencher Tony Burke in parliament on Thursday, opting to take some on notice while he sought more information.
Mr Burke was keen to link the prime minister to the appointment of Alastair Furnival, chief of staff to assistant Health Minister Fiona Nash.
Senator Nash has been under pressure to explain what role Mr Furnival played in the website being taken down just 20 hours after it began operating.
Mr Furnival retains a shareholding in the lobbying firm Australian Public Affairs, operated by his wife Tracey Cain, which represents food industry opponents of the website including Kraft and Cadbury.
Labor insists there has been a serious breach of the ministerial staff code of conduct and Labor Senate Leader Penny Wong has accused Senator Nash of misleading parliament "twice in three days".
Senator Nash denied the claim.
"The answers I provided to questions in the Senate today were absolutely correct," she said in a brief statement on Thursday night.
During question time Mr Burke had quizzed Mr Abbott about whether Senator Nash had revealed Mr Furnival's apparent conflict of interest to a meeting of the Australia and New Zealand Regulation Ministerial Council she chaired in December.
He also wanted to know why, given the "serious conflict of interest", the government had not reinstated the website.
Mr Abbott said it was taken down because it was not ready to go.
Senator Nash was asked nine questions about Mr Furnival during the Senate's question time.
The Senate was told a senior health department official with responsibility for the website, Kathy Dennis, was demoted six days after it was taken down.
The minister said the first she knew about the demotion was in an internal email.
She declined to reveal the date the prime minister's office approved the appointment of Mr Furnival and whether the shareholding was disclosed at the time and was on his private interest statement.
Senator Nash accused the opposition of "imputing impropriety where none exists".
"All the information about my chief of staff was given to the prime minister's office in accordance with appropriate timing," she said.
Later, Labor's health spokeswoman Catherine King told parliament the minister's explanations were not true.
When the website went live, all stakeholders were emailed to tell them it was online, she said.
Ms King also said an explanation that a ministerial council wanted a further cost-benefit analysis done was also untrue.
Senator Wong called on Senator Nash to explain the inconsistencies, prompting the denial statement from Senator Nash, who was not in the chamber at the time.
