On Wednesday, the Swedish Bar Association (Advokatsamfundet) criticized Lambertz for presenting his own “convincing evidence” and over his personal involvement in the case.
“It damages the Supreme Court and the whole Swedish judicial system,” said head of the association Anne Ramberg to news agency TT.
The comments come following the publishication on Wednesday of email exchanges Lambertz had with several lawyers involved in the case.
Quick, who has changed his name to Sture Bergwall, was previously convicted of eight murders committed between 1976 and 1988.
During therapy he admitted to eight murders along with more than 20 others committed in Sweden, Norway and Finland, often describing how he butchered his victims and in at least one case ate the body parts.
In December 2008, however, he suddenly withdrew all his confessions, saying he had been craving attention at the time and had been heavily medicated by doctors.
Questions have since been raised about the strength of the evidence used to convict him.
Retrials have been granted for another two cases, and in June the last three applications for retrial were submitted.
The emails published by Expressen were written in August when Lambertz, the former Chancellor of Justice, wrote an opinion piece in daily Dagens Nyheter (DN) calling for questions about mismanagement of the Quick case to be "cleared up to find out what went wrong, when, and why."
In the article, he presented what he referred to as “convincing evidence” against Quick in at least two of the murders for which Quick was acquitted.
However, the email exchange between Lambertz, prosecutor Christer van der Kwast and police officer Seppo Penttinen, reveal that Lambertz had started to doubt Quick's guilt shortly after a book about the case, penned by author Hannes Råstam, had been published.
“To be honest, I feel as if he has pulverized all our ‘incontrovertible facts'," Lambertz wrote in reference to the book in an email published by Expressen.
In his previous role as Chancellor of Justice, Lambertz was responsible for reviewing the work of investigators and prosecutors involved in Quick case, and concluded in 2006 that there was no reason to launch an probe into criminal negligence for how the case was handled.
The exchange includes discussions about the opinion piece Lambertz was planning to publish in DN, as well as participation in debate programmes on Swedish television and what question could be expected from the media.
Anne Ramberg is critical of the way Lambertz have acted in the Quick investigation, saying that it is self evident to her that a Supreme Court Justice can't act as a “private eye” on the side.
“I think that it is inappropriate and that it is sad. It also damages the Supreme Court and the judicial system,” she told TT.
Lambertz doesn't agree with Ramberg's criticism.
“Firstly, I am allowed to say these things as a Supreme Court Justice and secondly there is value in the criticism I have directed against the conclusions reached by the media,” Lambertz told TT.
He is also concerned over the actions of the press and publication of his emails in particular. He also feels that the media has been wrong in writing about the Quick case as a “legal scandal”.
“There is also the unwillingness to even consider that one might be wrong, attacked me left, right and centre and avoided the issue at hand,” Lambertz told TT.