Struggle stalwart Amina Cachalia and long-time friend of former president Nelson Mandela, has died.

She was 82.

According to reports, Cachalia – who spent 15 years in the 1960s and 1970s under house arrest, following three consecutive banning orders by the apartheid regime, died in Johannesburg's Milpark Hospital earlier on Thursday.

Cachalia was born on June 28, 1930, in Vereeniging and was the ninth child in a family of eleven children. Her family's tradition of political activism dates back to her father Ebrahim Asvat's close association with Mahatma Gandhi – who is considered the father of the Indian nation – and the first passive resistance campaign of 1907.

Her father was Gandhi's companion and the chairperson of the Transvaal British Indian Association, forerunner of the Transvaal Indian Congress (TIC).

Cachalia went to school in Durban and returned to Johannesburg towards the end of 1947. Due to her family's finances, she took up a number of jobs, including one as a secretary in a garment factory.

"Her experience as a woman in the workplace underlined for her the importance of financial independence and the need to amass skills and she founded the Women's Progressive Union (WPU) to foster training, skills development and the financial independence of women," a biography by Wits University said.

The union grew and flourished for four years under Cachalia's mentorship until she went to jail in 1952 during the Defiance Campaign.

In the 1950s she was an active member of the Peace Council and was politically active in the Indian Youth Congress, the Indian Congress and the Federation of South African Women (Fedsaw).

She was involved in organising the protest campaign against passes for women and was one of the leaders of the 20 000-strong march of women on the Union Buildings in Pretoria in August 1956. During the Treason Trial she was involved in looking after the dependants of the trialists.

"Amina pursued her political activities clandestinely and, as a result, was served with a restrictive banning order in 1963 while she was recuperating from a serious heart operation," the biography said.

Her underground activities continued throughout the period of her banning, which lasted from 1963 to 1980.

The Nelson Mandela Centre of Memory said Cachalia – the widow of political activist Yusuf Cachalia – had "travelled a long road" with Mandela and his family.

"She and... Yusuf were friends with Mr Mandela in the years before he went to prison.After he was imprisoned in 1962, they kept in touch through letters," the centre's chief executive, Achmat Dangor, said in a statement.

Only after he was transferred to Pollsmoor Prison was he finally allowed to be visited by the Cachalia couple

"They resumed their friendship after his release in 1990," Dangor said.

Cachalia was elected an MP in the National Assembly, in the first democratic elections of 1994.

Ten years later, she received The Order of Luthuli in Bronze for her lifetime contribution to the struggle for gender equality, non-racism and a free and democratic South Africa.

The African National Congress said Cachalia had played a crucial role iu the liberation movement.

"She played a critical role in mobilising women and radicalising their programme," spokesperson Jackson Mthembu said in a statement.

"As an individual she lived through the pain of police harassment, imprisonment, house arrests, banning and humiliation."

He said South Africa would "forever be indebted to her" and her family for her role in ensuring that South Africa became a democracy.

"She will always be remembered for her selflessness, steadfastness and commitment."

Democratic Alliance leader Helen Zille sent her condolences to the Cachalia family.

"Amina Cachalia was a brave struggle hero....she was determined and fought fiercely to overcome injustice and racial discrimination," she said in a statement.

"Amina was an inspiration to us all. May her life continue to inspire both women and men alike."

Ananth Singh, chief executive of Videovision Entertainment, said he was saddened by the news.

"Amina was a beacon in the liberation movement, a committed activist and an exceptional South African," he said in a statement.

"She and...Yusuf were key individuals in the movement and they also shared a close bond with Madiba and forged a friendship that endured over time."

Cachalia's political activism and championing of women's rights was almost preordained, according to Wits.

"... We have lost not only a freedom fighter but more importantly a human rights activist and a protector of the vulnerable," the institution said in a statement.

"Amina, and indeed her family, are close friends of Wits. In recognition of her achievements, the university bestowed its highest honour, an honorary doctorate of Laws on her in 2004, the same year in which the National Order of Luthuli was bestowed on her."