He was known as Donor 9623.

Parents were told he was healthy and well-educated. But he was a troubled man with multiple diagnoses of mental illness and a felony conviction. And his sperm is believed to have been used to conceive at least 36 children in Canada, the US and Britain.

Now three Canadian families have launched lawsuits against US sperm bank Xytex and its Ontario distributor, Outreach Health, alleging they were misinformed about their sperm donor.