Winnie Madikizela-Mandela, ex-wife of former president Nelson Mandela, listens to testimony at an amnesty hearing of the Truth and Reconcilliation Commission in Johannesburg on Nov. 29, 1999. ((Associated Press))

Winnie Madikizela-Mandela, ex-wife of former South African leader Nelson Mandela, has been denied entry to Canada.

Madikizela-Mandela was scheduled to attend a fundraising gala in Toronto on Tuesday for the arts organization MusicaNoir.

The CanadianHigh Commissionin South Africa has refused to grant a visa for Madikizela-Mandela, according to Carole Adriaans, a spokeswoman for MusicaNoir, which promotes diversity in classical music.

No reason was given, Adriaans said.

"She was devastated. We were devastated. We are devastated," Adriaanstold CBC Radio.

Madikizela-Mandela, 70, is controversial because of the violence practised by her supporters in the struggle against apartheid.

In 1991, she was convicted of kidnapping and assault in connection with the death of a 14-year-old activist.

Her lifestory is the subject of a new two-part opera being staged in Toronto as part of the Luminato arts festival.

The Passion of Winnie (Part One) was created by composer Bongani Ndodana-Breen and filmmaker Warren Wilensky. It was scheduled to be performed as part of the Toronto gala, A Night in Soweto, that Madikizela-Mandela had plannedto attend.

Organizers say the fundraiser will go ahead as planned with another special guest, LeVar Burton, an African-American actor, director and author.

South African-born Wilensky said Canada's decision underlines the reason he wrote the opera.

"[At] the end of the day, I want people to walk away saying, 'I would not judge someone until I walked a mile in their shoes,' and again, people are judging her," he said. "The Canadian government's taken a stand."

Criminal record may have kept Mandela out

Mandela's criminal conviction may have been enough to keep her out of Canada.

"Generally, if you have a criminal record, you're not wanted in this country, either for permanent residence or to visit as a tourist," immigration lawyer Guidy Mamann told CBC Radio.

Celebrities with criminal records can apply for a minister's permit and still get into the country, as was the case with Martha Stewart.

Madikizela-Mandela was in New York City just two weeks ago to accept an award for her work with AIDS and the Save Africa Concerts Foundation affiliated with the United Nations.

Madikizela-Mandela had a public falling-out with her husband, anti-apartheid fighter and former South African president Nelson Mandela, after he formed a new government in 1995. They divorced a year later.

She was scheduled to travel to Canada with Zindzi Mandela, Nelson Mandela's daughter.