The police officer who headed up the Baden-Clay murder investigation has not ruled out claims that police bugged Allison Baden-Clay's coffin in the hope of extracting a private confession from her husband Gerard.
Det-Supt Brian Wilkins revealed police were "immediately suspicious" of the 43-year-old in the days after his wife's disappearance in April 2012 because his face was scratched and "things did not add up".
Speaking yesterday, the day after Baden-Clay was convicted of his wife's murder and sentenced to life in jail, Det-Supt Wilkins told 612 ABC Brisbane that "wide and varied strategies" were used to gather evidence.
He would not comment on reports flowers on the coffin were fitted with a microphone before Mrs Baden-Clay's funeral in the hope Baden-Clay might break down and confess if he was alone with the coffin.
"I'm not in a position to talk about methodologies that we utilise," Det-Supt Wilkins said. "The investigation is in relation to a very, very serious crime and the police will use whatever lawful tactic we have to gather evidence to sustain a conviction and place a person before the court."
Queensland Police Commissioner Ian Stewart said the case took a heavy emotional toll on investigating officers, particularly those who interviewed the couple's young daughters after Mrs Baden-Clay's disappearance.
"That's one of the toughest jobs you could ever ask anyone to do," Mr Stewart told Southern Cross radio. "They become very emotionally involved in some of these things. We have mechanisms in place. We check in with them to make sure that emotionally, they're OK. A lot of our people have kids the same age."
Their comments came as a criminal law expert said Baden-Clay would "almost certainly appeal" against his murder conviction and minimum 15-year sentence.
Professor Heather Douglas from the University of Queensland said Baden-Clay's legal team would be poring over transcripts of his 21-day trial to find grounds for an appeal.
Under Queensland law, there are three avenues of appeal - one being error of law, as in whether the judge has made incorrect directions to the jury.
Another is if it can be shown the jury reached a "dangerous" verdict out of step with the evidence. The third is miscarriage of justice, which can cover a variety of scenarios including whether jurors have been found to do research outside the court-room or if any evidence was prejudicial against the defendant.
Baden-Clay has 30 days to lodge an appeal or apply for an extension of time to lodge an appeal.
More reports emerged yesterday alluding to Baden-Clay's personal life and extramarital affairs including suggestions he turned to the internet for sex.