Valery Fabrikant is serving a life sentence for killing four colleagues at Concordia University in Montreal in 1992. ((Radio-Canada))

Convicted killer Valery Fabrikant was back in a Montreal court Monday after a break of more than three years, pursuing his lawsuit against engineering-department colleagues at Concordia University.

Fabrikant is serving a life sentence for shooting to death four of his faculty colleagues in 1992.

In his $600,000 lawsuit, he claims other university staff members unfairly profited from his research, and they "extorted" his documents.

The lawsuit was thrown out in 2007, but Quebec's Court of Appeal said that was done in error and ordered it to resume.

In most of his court appearances, Fabrikant has complained about a variety of things unrelated to the case, so much so that Justice Gilles Hébert quit hearing it in 2007.

On Monday, Fabrikant complained about his leg irons, cold feet, parka and what he called his filthy cell.

Judge François Roland said he would announce his response to the complaints when court sits again Tuesday.

He then told Fabrikant he could question his former colleague, Tom Sankar, who was on the stand.

Fabrikant asked Sankar to explain why the number of scientific papers he published had doubled after Fabrikant was hired by the university.

Sankar told the court many people contributed to papers.

He also said he severed ties with the university a few years after the murders out of a sense of guilt. He said everyone associated him with the crime because he had recommended that the university hire Fabrikant.