Steven Avery at the Calumet County Courthouse in Chilton, Wisconsin in 2007 Picture: AP Photo/Morry Gash

Lawyer Jerry Butin appeared in Making a Murderer, the Netflix documentary that has made his client a celebrity and cast doubt on his guilt.

Avery has now filed an appeal of his murder conviction through the Wisconsin Court of Appeals.

He reportedly believes that a juror may have tainted his chances of a fair trial by constantly referring to him as “f***ing guilty” and turning the other 11 jurors against him.

Avery further alleges that police illegally obtained evidence and may have planted evidence at the crime scenes, to which they had insufficient warrants.

In an interview with Rolling Stone, Butin has clarified some of the comments he made in the documentary, specifically his concerns about the jury.

At the end of the series, Butin said of the jury: “I’ve still got my suspicions about whether something improper occurred during the deliberations”.

Since then, at least one juror has come forward to say they believed Avery was not guilty of the murder of photographer Teresa Halbach, 25, and only convicted him because “they feared for their safety”.

Butin told Rolling Stone that a juror who was let go after the first day of deliberations said the initial vote was seven not guilty, three guilty and two undecided.

But this information has since been denied by another juror interviewed by local media.

“I can’t prove anything at this point,” Butin said, but added “(There are) just some indications that we had that there might have been some other individuals that had some, if not direct, then indirect, influence on them.”

Butin also shed light on the jury selection process, saying that the state “pretty obviously” tried to strike jurors who were educated.

“We were looking for jurors who were intelligent, independent, had some significant education so that they could follow the science, and the state, obviously, was not.”

Meanwhile the filmmakers say they expected a backlash that would lead people in the media to demonise Avery.

Steven Avery, right, in the Netflix documentary series Making A Murderer. Picture: Netflix via APSource:AP

The case has captivated the public’s imagination ever since the screening of Making a Murderer, which has influenced many to take up Avery’s cause. More than 400,000 people have signed a change.org petition calling for the US President to pardon the Wisconsin man.

Avery previously served 18 years in prison after being wrongly convicted for rape. He was released in 2003 due to DNA evidence and lodged a $US36 million lawsuit against officials when he was arrested for murder.

During a news conference on Sunday, filmmakers Laura Ricciardi and Moira Demos sought to deflect discussion on the question of Avery’s guilt or innocence and instead pointed to questions raised about the criminal justice system in their film.

Prosecutors — who the filmmakers say declined their request to participate in Making a Murderer — claimed the film omits physical evidence against Avery. A former fiancee of Avery’s, Jodi Stachowski, told HLN this week that Avery was “a monster” who had threatened to kill her.

Ricciard and Demos said they expected that reaction.

“The media are demonising this man in order to prove his guilt,” Ricciardi said.

Steven Avery’s ex Jodi Stachowski said she thought Avery was guilty in an interview with Nancy Grace. Picture: HLNSource:Supplied

Although they said they were filmmakers, not prosecutors, they said they tried their best to reflect all of the facts in the case.

They ducked questions Sunday on their belief about Avery’s guilt or innocence, even though they told Stephen Colbert on CBS’ Late Show earlier this month that they believed he was not guilty. Ricciardi said she would not want to be treated by the criminal justice system the way Avery was.

“We did not consider this advocacy journalism in the least,” Demos said. “We are not taking sides. We don’t have a stake in his character, in his innocence or guilt. That was not the question that we were raising.”

She said that “if you watch the series, I think it’s clear that the American criminal justice system has some serious problems and that it is urgent that we address them.”

But despite the attention around his conviction, Avery may not even have seen the documentary that has made him a household name.

Avery was convicted of the murder of Teresa Halbach. Picture: AP Photo/ Halbach Family via Herald Times ReporterSource:AP

“Steven does not have access to the series,” Ricciardi told The Hollywood Reporter. “He asked the warden and his social worker whether he’d be able to see it and his request was denied.” They said they have had conversations with Avery since the documentary’s release that they have taped, but have not returned to Wisconsin for more filming.

“We are ready to follow if there are significant developments and we are looking at other stories, as well,” Demos said.

Netflix chief content officer Ted Sarandos hinted on Monday that Making a Murderer could get a second season.

“The story is still unfolding, so well certainly take a look at it,” Sarandos said.