A lesbian couple, married shortly after the province of Ontario legalised marriage equality in June 2003, successfully filed for the first known legal divorce of a same-sex couple anywhere, the Canadian newspaper Globe and Mail reported Tuesday.

The couple, whose names were kept confidential, had been together for more than 10 years, but filed for divorce within a week of marrying.

Ontario Superior Court Judge Ruth Mesbur struck down the section of the Divorce Act after finding the legal definition of spouse - in terms of heterosexual married couples - to be "unconstitutional, inoperative and of no force and effect."

It puts put same-sex couples in the bizarre position of being able to get married but unable to legally split up.

"We believe this is not just the first gay or lesbian divorce in Canada, but actually the first gay or lesbian divorce in the world," Martha McCarthy, attorney for one of the women, told the Globe and Mail.

It is unclear whether Judge Mesbur's judgment of the Divorce Act as unconstitutional will be limited to Ontario or take effect nationwide.

Same-sex marriage was legalised in Yukon Territory in July and the provinces of Ontario, Quebec, British Columbia in 2003 and most recently in Manitoba, on Thursday. The federal government is however awaiting an opinion from the Supreme Court of Canada on same-sex marriage, before going ahead with changes to laws.