South Africa's governing African National Congress has demanded an apology from the US to its senior member arrested last week at JFK International Airport in New York for being on America's terrorist list.
In a statement released on Monday, the ANC also condemned Tokyo Sexwale's detention, saying he was "a decorated freedom fighter, activist and leader of our liberation movement, not a terrorist".
Sexwale, a cabinet minister in President Jacob Zuma's government until July when he was fired in a cabinet reshuffle, was arrested while on a trip to the US.
He along with Nelson Mandela, South Africa's first black president and an anti-apartheid icon, were jailed on the Robben Island by the white minority government that accused them of waging a terror campaign to bring down the regime.
The names of both men ended up on the US terrorist list, with Mandela's getting removed only in 2008 by former President George W Bush while Sexwale's remained on the list. Other prominent South African freedom fighters have also been arrested in recent years.
It was not immediately clear whether Sexwale, a wealthy politician and businessman, had travelled to the US for the first time.
"The very fact that the Government of America continues to view members and leaders of the African National Congress as terrorists is an affront to the global anti-apartheid movement, in which many compatriots from the United Nations including that country's sitting president, were part of," the ANC statement said.
"The African National Congress toiled selflessly with the people of America, despite their government`s opposition at the time, for the liberation of the people of South Africa."
The statement singled out the 1966 UN General Assembly resolution 2202 A (XXI), which it said labelled apartheid as a crime against humanity.
"Both the General Assembly and the Security Council that the United States is a member of regularly condemned apartheid," the statement said.
"It is inconceivable therefore that today, the African National Congress and/or its members and leaders, who were at the forefront of the struggle against apartheid, are regarded as terrorists by America."
The ANC said the apology to Sexwale and South Africans should be "unconditional" and that the US should remove Sexwale's name from "terrorist profiling lists".
Sexwale served as human settlement minister but has been at loggerheads with Zuma, and was sacked along with two other ministers in July’s reshuffle.
Details on the case were scarce. US officials would not comment on whether or why Sexwale was held, Associated Press news agency reported.