Bangladesh released opposition leader Khaleda Zia from jail on Wednesday for six months to allow the two-time former prime minister to undergo urgent medical treatment.

Zia has spent more than two years behind bars for corruption but her Bangladesh Nationalist Party claims her conviction was politically motivated.

The 74-year-old is the bitter rival of current premier Sheikh Hasina, and the families of both women have dominated the country's politics since independence in 1971. Hundreds of Zia's supporters greeted her in the capital Dhaka -- defying a government ban on public gatherings to contain the coronavirus outbreak -- as she emerged in a wheelchair from a hospital where she had been kept confined in a special cell.

"She is very sick and she will now be treated by top Bangladeshi doctors," BNP vice-chairman Zahid Hossain told AFP. Zia's release was granted on the condition that she stayed in Dhaka for treatment of her diabetes and arthritis. Her family had appealed for her to be allowed to go to Britain for treatment.