Sri Lanka, July 9 -- A deadly crackdown on student-led protests in Bangladesh last year was authorised by then prime minister Sheikh Hasina, according to audio of one of her phone calls reportedly verified by the BBC.

In the audio, which was leaked online in March, Hasina says she authorised her security forces to "use lethal weapons" against protesters and that "wherever they find [them], they will shoot".

Prosecutors in Bangladesh plan to use the recording as crucial evidence against Hasina, who is being tried in absentia at a special tribunal for crimes against humanity.

Up to 1,400 people died in last summer's unrest, according to UN investigators. Hasina, who fled to India, and her party reject all charges against her.

A spokespe...