Sajeeb Wazed Joy, son of Bangladesh's ousted Prime Minister Sheikh Hasina, has rejected a United Nations report claiming that up to 1,400 people were killed during last year's mass uprising, saying the actual number was closer to 800.

In an interview with The Associated Press published Wednesday, Joy acknowledged "some initial mistakes" by the Hasina-led government during the protests but insisted that the figures reported by the UN were inflated.

He cited a statement from a health adviser under Nobel laureate and current interim leader Muhammad Yunus, who reportedly said that around 800 people had died.

"All the deaths were regrettable and need thorough investigation," Joy said, adding that the interim government's decision to grant immunity to protesters involved in last year's violence raises further questions about accountability.

He also accused the Yunus administration of using the uprising as a pretext for a "witch-hunt" against his mother, who faces multiple charges, including crimes against humanity.

Last week, a prosecutor at a special domestic tribunal sought the death penalty for Hasina. She has refused to appoint lawyers to represent her, calling the trial a "kangaroo court," said Joy.

He warned that Bangladesh's political instability would worsen unless the interim government lifts its ban on the Awami League, which was imposed in May.

"This ban has to be lifted, the elections have to be inclusive and free and fair," he said, accusing the government of trying to bar his mother and other party leaders from contesting the polls.

"What is happening now really is an attempt to keep my mother and our political leaders from running in elections. This is political manipulation disguised as justice," he told AP from Washington, DC.

He further alleged that Yunus was paving the way for Islamist groups to gain power by "backing them and planning a rigged election."