BNP chairperson Khaleda Zia
File photo

The UN rights chief Volker Turk has urged Bangladesh prime minister Sheikh Hasina to release main opposition leader Khaleda Zia for urgent medical treatment outside the country.

Bangladeshi physicians have said Zia, a two-times former premier, was at "high risk" of dying without overseas medical intervention abroad after the Hasina government rejected pleas to let her leave.

Zia, 78, heads the main opposition Bangladesh Nationalist Party (BNP) and has been living under effective house arrest since her release from a 17-year prison sentence in 2020.

The two women are known as the Battling Begums and their internecine rivalry has dominated the politics of the South Asian nation of 170 million people for over four decades.

Turk, the UN High Commissioner for Human Rights, said in a letter to Hasina that Zia's release would be seen as "an important step towards political dialogue and reconciliation".

"I appeal to your government to consider her release to enable her to receive the urgent and specialised medical care that she requires outside of the country," he wrote in the letter dated 1 November and seen by AFP.

Zia has advanced liver cirrhosis, diabetes and heart problems. Three US physicians carried out minor surgery on her last month, but the government rejected a family request to allow her to travel to Germany for a liver transplant.

The country is gearing up for general elections due in January, with the opposition holding regular protests, and Zia's death would likely trigger huge demonstrations.

Hasina, who has been in power for nearly 15 years, faces mounting pressure from Western powers to hold free and fair elections, which could set the stage for a comeback by Zia's resurgent BNP.

Turk also asked the government "to prevent any arbitrary detention including detention that could be perceived as politically motivated or which might impact the environment for fair and credible elections".