UN calls for independent inquiry into death of ex-Egyptian president Mohamed Morsi

United Nations officials have called for an independent inquiry into the death of ousted Egyptian president Mohamed Morsi.

The 67-year-old collapsed and died in a Cairo courtroom on Monday after reportedly suffered a heart attack. He was on trial for alleged espionage at the time.

Mr Morsi was Egypt's first democratically elected president and had been held in custody since he was ousted by the military in 2013.

He was laid to rest under heavy security at a cemetery in Cairo's western district of Nasr, after his family was refused permission to bury him in his hometown in Sharqia province, according to Mr Morsi's son Ahmed.

The UN's human rights office has called for a "prompt, impartial, thorough and transparent" investigation into Mr Morsi's death, while Human Rights Watch (HRW) says he was mistreated and suffered "years of insufficient access to medical care".

Sarah Leah Whitson, HRW's Middle East director, said ex-president's treatment in prison was "horrific".

"At the very least, the Egyptian government committed grave abuses against Morsi by denying him prisoners' rights that met minimum standards," she added.

Ahmed Morsi has also previously spoken with the media about the "severe deterioration" of his father's health in prison.

On Tuesday, mosques across Turkey mourned the death of Mr Morsi, while several hundred people in Ankara held a protest outside the Egyptian embassy.

Speaking at an Istanbul mosque, Turkish president Recep Tayyip Erdogan said he did not believe Mohamed Morsi died of natural causes.