11/03/2016 1:08 PM AEDT | Updated 15/07/2016 12:51 PM AEST

'Throw The Key Away': Denise Morcombe's Relief As Son's Killer Loses Last Appeal Bid

Chris Hyde via Getty Images
SUNSHINE COAST, AUSTRALIA - AUGUST 29: Denise and Bruce Morcombe pose for a photograph outside Daniel Morcombe foundation house on August 29, 2011 in Sunshine Coast, Australia. DNA tests have confirmed that bones found by local authorities at the bushland site at Beerwah are the remains of Daniel Morcombe. A 41 year old man has been charged with Daniel's 2003 murder, deprivation of liberty and child stealing. (Photo by Chris Hyde/Getty Images)

"Throw the key away and I never want to hear that name again."

These were the words of Denise Morcombe after her son's killer, Brett Peter Cowan, lost his application for appeal in the High Court on Friday.

This was the last legal avenue for Cowan, who will now serve his full sentence of life in prison. In 2014 the 46-year-old was convicted of the 13-year-old Sunshine Coast boy's murder in 2003.

Yes, 2003. As Denise Morcombe said on Friday morning after the High Court appeal bid was put to bed, it took almost eight years for police to get a confession out of Brett Peter Cowan. And this confession is what Cowan's lawyers argued gave the 46-year-old grounds for appeal.

His admissions to killing Daniel were caught on tape by undercover police posing as gangsters, with Cowan's lawyers arguing the 46-year-old was unfairly target by authorities.

In 2014 Brett Peter Cowan lost his appeal for conviction at the Queensland Court of Appeal. Cowan's lawyers then applied for special leave to appeal to the High Court, which was lost on Friday morning.

"While it's a sad story, at least we've got a full stop to that," Bruce Morcombe told reporters after the final hearing.

Bruce said Cowan's appeals were "a waste of the public purse".

"Today's proceeding is a bit of an eye opener to the legal obstacles before us at the courts.

"There was not one word uttered that said 'You've locked up an innocent man'.

"We had a guilty man. He's been behind bars for four years. He was found guilty almost to the day two years ago and yet appeal after appeal the system winds on. I don't think that's right."

Bruce asked the nation to not forget Daniel's name.

"We can use Daniel's tragic story to make sure future kids are safe."

As Denise Morcombe tweeted on Friday, RIP Dan.