In what has become the biggest twist to "Making a Murderer," a Wisconsin prisoner has allegedly confessed to the murder of photographer Teresa Halbach in 2005. Halbach's murder was the subject of the controversial but popular Netflix series "Making a Murderer" documentary. If proven true, it could potentially pave the way for convicted killer Steven Avery's exoneration.

The confession's legitimacy is still being investigated by many people including Avery's own appellate lawyer. Avery and his nephew Brendan Dassey were eventually convicted of murdering Halbach.

Shawn Rech, the director behind an upcoming documentary of this case, was the one who broke the news about the alleged confession.

Investigators still examining the taped confession

The audio confession is being examined as well, as investigators are looking into the background of the individual who confessed. The producers behind the upcoming 'Convicting A Murderer' received the audio confession from a "notable convicted murderer" from Wisconsin. The confession has been sent to law enforcement and legal teams for analysis.

The producers are conducting their own investigation into the legitimacy of the taped confession as they continue their work on the 10-part series. Because the confession comes from a notable murderer, the producers felt it responsible to hand over any possible evidence to law enforcement and the legal teams.

Former District Attorney Ken Kratz, who was the original prosecutor on the case, took to Twitter to say that he has no comment on the confession until he is able to see all the details. Lawyers for both Avery and Dassey continue to challenge their convictions, claiming everything from coercive interrogation techniques and messed-up blood evidence.

'Making a Murderer' became Netflix's most popular true-crime documentary

The first season of the documentary became a massive Netflix success and includes behind the scenes footage of the Avery family. The documentary was set up on the possibility that Avery and his nephew Dassey, may have been framed by a system that was still angered by Avery's previous exoneration for a rape he didn't commit.

Avery was in prison for years, until DNA evidence proved another man committed the crime.

While it was popular, it did attract its fair share of critics. Some argued that it left out key pieces of evidence against Avery including blood evidence found in Halbach's car. Law enforcement alleges that they found a bullet with Halbach's DNA on it in Avery's garage. Avery's defense team argued it was all planted.

While Avery was convicted based on forensics, his nephew was convicted based solely on a series of confessions. Defense lawyers have argued that the confessions were coerced from Dassey. Dassey was never forensically tied to the slaying.