Neill-Fraser is serving a 23-year sentence for murdering her partner Bob Chappell in 2009.

Mr Chappell's body was never found after disappearing from his yacht, and Neill-Fraser's supporters maintain she is innocent.

Last week, hundreds gathered on Parliament House Lawns to mark the fifth anniversary of her arrest.

Former Integrity Commission boss Barbara Etter and Denison independent MHR Andrew Wilkie have called on the government to review the case.

A 60 Minutes report that aired on Sunday night explored a new theory into Mr Chappell's disappearance, claiming he may have been the victim of a violent burglary, and DNA found on the boat belonging to a homeless woman was not properly considered by police.

Inspector Peter Powell, who was the chief investigator of the case, said the 60 Minutes story was biased.

"There were inaccuracies in the story regarding the evidence presented at the trial, and the report failed to mention any of the evidence that points to the guilt of Neill-Fraser," Inspector Powell said.

"It's important to point out that Neill-Fraser was found guilty by a Supreme Court jury, her appeal was dismissed and a coroner's investigation, which reviewed all the available evidence, supported the findings of the criminal proceedings," he said.

Inspector Powell said Tasmania Police had no concerns about the soundness of the judgment, the investigation, or the evidence tendered to the court.

His comments relieve the pressure mounting on Attorney-General Vanessa Goodwin to refer the case back to the Court of Criminal Appeal.

Dr Goodwin said yesterday that she had not received a mercy petition.

"A petition for mercy is the proper mechanism to determine whether further review of the conviction is warranted," Dr Goodwin said.

"If I receive a petition for mercy in relation to Ms Neill-Fraser it will be considered at that time and in accordance with the law," she said.