A man in Hamilton who had unprotected sex with at least 12 women without telling them he was HIV-positive has been charged with first-degree murder after two of the women died.

Johnson Aziga is thought to be the first person in Canada to face that charge in connection with spreading the deadly virus.

The 48-year-old Ugandan-born man had earlier been charged with endangering the lives of his sexual partners, seven of whom later tested positive for the virus that causes AIDS.

The two first-degree murder charges were laid after two women in Toronto died, in December 2003 and in May 2004.

A variety of courts have ruled that if people don't know their sexual partner carries the AIDS virus, they cannot truly consent to sex.

As a result, the deaths of the two women are considered to have resulted from sexual assaults. That automatically calls for first-degree murder charges as opposed to lesser charges such as manslaughter.

The case returns to court on March 11.