The United States and Britain have strict no-ransom policies, but other countries, including France and Germany, have taken suitcases of cash to the desert to win the freedom of their citizens. The expenditures were disguised as “humanitarian aid to Africa.”

The group that held Mr. McGown emerged as Al Qaeda’s official branch in North Africa over a decade ago, rising to prominence in large part because of the extraordinary sums it garnered from ransoms. Starting in 2003, with the abduction of 32 European tourists who were freed after government payments estimated to total €5 million, the group has kidnapped dozens of foreigners, including travelers, aid workers and journalists.

Few people were released without a payment of some kind or some form of prisoner swap. Ransoms in at least some of the cases were negotiated directly by Al Qaeda’s central leadership in Pakistan and Afghanistan.

Mr. McGown was freed a few days ago in northern Mali, an area dominated by Islamist militants.

He was taken hostage on Nov. 25, 2011, along with two European tourists: Sjaak Rijke of the Netherlands, who was freed by French commandos in Mali, and Johan Gustafsson of Sweden, who was released in June.

In their capture, the men were taken from the inn and herded into a truck at gunpoint. A fourth man — a German tourist who refused to get into the truck — was killed on the spot. Mr. Rijke’s wife survived the raid; the gunmen evidently did not notice her.

Ms. Nkoana-Mashabane, the foreign minister, declined on Thursday to discuss the condition of Mr. McGown, now back in South Africa. “Is he receiving the necessary support — the requisite for any South African citizen who had gone through this very, very painful experience? The answer is yes,” she said.

She pleaded with journalists to “allow him to resettle and regain his freedom.”

Militants released a video showing six captives, including Mr. McGown, last month, before a visit to Mali by President Emmanuel Macron of France. Mr. McGown also holds a British passport.