Making a Murderer's Steven Avery wins right to appeal as lawyer claims evidence has potential to 'undo whole case'

Steven Avery, whose murder conviction was the focus of the popular Netflix series Making a Murderer, has won a motion to appeal his conviction.

The latest development was hailed as a “big win” by the convicted killer’s lawyer, who claims she has evidence that has the potential to “undo the whole case”.

Avery is serving a life sentence for the murder of young freelance photographer Teresa Halbach, whose charred remains were found at Avery’s car salvage yard, in 2005.

He denies murder and won the appeal motion based on possible human bones found in a gravel pit. His lawyer, Kathleen Zellner, who filed the motion, said the bones were not tested for DNA and were given to the Halbach family, a violation of state law.

Convicted: Steven Avery is serving a life sentence for murder
Netflix/Rex

”This evidence has the potential to undo the whole case, so it is a big win,” Ms Zellner told Newsweek.

"The case is being remanded back to the circuit court to conduct proceedings, which can include a hearing. The circuit court can grant a new trial, or if not, back to appellate court who can reverse the conviction and/or grant a new trial."

The lawyer said the case is being remanded back to the circuit court for proceedings, which could include a fresh hearing.

On Twitter, Ms Zellner said: "We are going to have an extraordinary number of constitutional violations when we are done. The COA [court of appeal] is letting us create an avalanche of evidence in this record. Higher courts rule."

Avery was convicted in 2007 of killing Ms Halbach. His nephew Brendan Dassey was also found guilty of murder.

Avery was previously jailed for 18 years for sexual assault, but was cleared in 2003 after new DNA evidence showed he had no involvement in the attack.

He has always protested his innocence to both crimes but was handed a life sentence after being found guilty of murder by a jury.