The man jailed for killing Queensland schoolboy Daniel Morcombe has had his appeal against his conviction dismissed.

Brett Peter Cowan was in 2014 sentenced to life in prison with a non-parole period of 20 years for killing 13-year-old Daniel in 2003.

Cowan abducted Daniel while he waited for a bus on the Sunshine Coast.

His lawyers launched an appeal on six grounds including potential prejudicial media during the trial and that police improperly obtained a confession.

Queensland's former attorney-general Jarrod Bleijie lodged a separate appeal to increase Cowan's non-parole period, which he said was manifestly inadequate and would fail to deter others.

Court of Appeal President Margaret McMurdo delivered the judgment dismissing Cowan's appeal, and also that of the attorney-general's to increase his sentence.

Lawyer Tim Meehan spoke to media outside Brisbane's Court of Appeal. ( ABC News: John Taylor )

Cowan's lawyer Tim Meehan said he was not overly positive that he could have won.

"He was realistic," Mr Meehan said outside court.

Mr Meehan said he would take instruction from Cowan on whether to pursue an appeal further.

When asked if Cowan was open to taking it further, Mr Meehan replied: "Yes."

"Available to him is a special leave application to the High Court, and that's what we will be pursuing," he said.

"We need to examine the decision of the court, the reasons for their rulings, obtain some instructions in relation to that, give advice to our client in relation to the reasons of the court, and that will determine what we do from here."

Mr Meehan said the heart of an appeal in the High Court would be the undercover police operation, which garnered a confession from Cowan.

"We believe the police officers in this particular operation overstepped the mark and their illegality rendered the admissions inadmissible," he said.

Morcombes hope Cowan is 'locked up for life'

Bruce Morcombe, father of Daniel Morcombe, hopes it is the last of Cowan's appeal. ( AAP: Dan Peled )

The public gallery was nearly full for the judgment.

Daniel's father Bruce was present, but his mother Denise did not attend.

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Mr Morcombe said it had been more than 11 years since they saw Daniel and they would never forget him.

"Today we hope that Mr Cowan doesn't forget his actions," he said outside court.

"He will spend 20 years in jail and we hope they are tough.

"He's locked up probably for the rest of his life and truly we hope it is the entirety for his life.

"It's very mixed emotions, really, it has been a long process.

"It is not a moment of celebration, but reflection.

"It is relief, but who knows, it may not be the end. We will wait and see."

Court dismisses claim against confession

Bushland in the Sunshine Coast hinterland where police searched for Daniel Morcombe's remains. Markers show location of items of interest. The image was presented as evidence in the trial of Brett Peter Cowan. ( AAP Image/Queensland Courts )

Justice McMurdo said the argument that Cowan's confession should not have been admissible did not have legs, as there was no abuse of power.

"It can be accepted that the appellant would not have made the admissions had he known the true identity of the undercover police officers," she wrote in the judgement.

"But they were not exercising the coercive power of the state when he confessed.

"He believed he was amongst his criminal friends.

"They stressed the need for him to tell the truth so that they could help him.

"He was free to leave their company at any time.

"They were not threatening or violent and in truth had not committed offences with him."

Justice McMurdo also ruled that the 20 year non-parole period would remain.

"The sentence is not manifestly inadequate," she said.

"There was no previous instance in Queensland where the parole eligibility date for a single murder was postponed beyond 20 years."

The appeal was overshadowed last week by a rift between Justice McMurdo and Chief Justice Tim Carmody, who withdrew from hearing the appeal.

Cowan's legal team alleged there was a perception of bias after Justice Carmody met with child protection advocate Hetty Johnstone before the judgement was delivered.