A criminal trial linked to one of the biggest public health scandals in Canadian history wrapped up in a Toronto courtroom Monday.

More than 20,000 Canadians contracted HIV or hepatitis C from tainted blood products administered during the 1980s and early 1990s.

Former Canadian Red Cross chief Dr. Roger Perrault, two senior Health Canada officials, New Jersey-based Armour Pharmaceuticals Co. and one of its executives have all pleaded not guilty to charges of criminal negligence.

Lawyers finished their final arguments Monday. Ontario Superior Court Justice Mary Lou Benotto is expected to deliver her verdict Oct. 1.

"Before this trial, I watched three quarters of my friends die as a result of receiving contaminated products," survivor James Kreppner, appearing frail and thin outside the courthouse, told CTV News.

In 1985, he became infected with HIV and hepatitis C while seeking treatment for hemophilia. Fellow survivor Mike McCarthy contracted hep C the year before.

They followed the trial closely but said they were concerned the Crown's legal team may have been outmatched. Eddie Greenspan, who helped defend Conrad Black in Chicago, and his brother Brian are just two of the high-profile defence lawyers.

"Unfortunately, the Crown sent a lot of good foot soldiers but the defence sent generals," said McCarthy.

Charges were laid in 2002 following an eight-year, multi-million-dollar investigation by the RCMP. But the trial was delayed as Perrault's health deteriorated.

Perrault suffered his first heart attack in 1980 and has undergone a series of operations, including angioplasty to unblock a coronary artery, bypass surgery and emergency surgery for an aneurysm.

The Canadian Red Cross is no longer involved in blood distribution. In 1998, that responsibility was transferred to Canadian Blood Services and Hema-Quebec.

With a report from CTV Toronto's Chris Eby