Canada has denied a visa to Winnie Madikizela-Mandela, the South African anti-apartheid leader and ex-wife of former president Nelson Mandela.
She had packed her bags and was about to set out for the airport when the Canadian embassy notified her that she would not be allowed to enter the country.
She was scheduled to be the keynote speaker at a fund-raising gala in Toronto tonight, where excerpts from a multimedia opera called 'The Passion of Winnie' would be shown.
'No reason was given' for the visa denial and immigration officials in Ottawa were not immediately available to comment.
Ms Madikizela-Mandela had just been to New York on 19 May to receive an award for her work on AIDS.
The 70-year-old, who rose to heroine status as a fearsome opponent of South Africa's apartheid regime, became a controversial figure because of her 1991 conviction in the death of a 14-year-old activist.
She also had a public falling out with her husband after he formed a new government in 1995. They were divorced a year later.
