The incredible allegations against Dr Norman Barwin are backed up by DNA tests which claimants say prove he is the biological father of at least 11 people whose parents went to him for fertility treatment.

Now 50 of the wronged children are taking him to court in a class action suit with support of lawyers Peter Cronyn and Frances Shapiro.

They include 16 people whose DNA allegedly matches neither Dr Barwin nor the intended donor, and 35 people who were supposed to be conceived using anonymous sperm but do not match the donor.

The doctor, who is based in Ottowa, was previously sanctioned in 2013 for impregnating three patients with the wrong sperm.