Golbarnezhad, 48, died after crashing during the C4-5 cycling road race in Pontal, a small peninsula and beach area in the Recreio dos Bandeirantes neighborhood, located in the West Zone of the city. 

He suffered a cardiac arrest on the way to hospital after incurring a head injury following a collision with a rock while descending midway through the race. 

An investigation into the circumstances of the accident has been launched.

"Yesterday's passing of cyclist Bahman Golbarnezhad has caused huge pain in my heart and I can only imagine what his wife and his son must feel like, waking up this morning and sadly knowing that yesterday was not a horrendous dream," said Sir Philip at a press conference ahead of this evening’s Closing Ceremony.

"Although yesterday's events do cast a dark shadow over these Games, I think Rio 2016 will be remembered as a successful Paralympics and Games which surprised many people.

"They will be remembered as the people's Paralympics."

Golbarnezhad's death is the first in competition at the Paralympics.

The last death in the Olympics came at Vancouver 2010 when Georgian luger Nodar Kumaritashvili suffered a fatal crash during a training run.

"Are athletes more daring?" said Sir Philip. 

"The athletes have always been daring but when something of this nature happens the IPC will have an initial investigation.

"The UCI (International Cycling Union) will be generating that report with the other authorities.

"We will look at what might need to be done for the future."

Asked whether budget cuts to the Paralympic Games affected the medical care to athletes, Sir Philip added: "There were no cuts that affected this.

"The ambulance that attended did so within two minutes.

"It was the latest ambulance that had all intensive care on it."

Masoud Ashrafi, secretary general of the Iranian National Paralympic Committee, said a request has been made to the IPC for the return of Golbarnezhad‘s body to Iran today and a report on the details of the circumstances that led to his death.

Piers Jones, the UCI’s sports director, claimed the road on which the accident occurred was in the condition it should have been.

"There were no issues with debris or foreign objects on the road," he said.

"We are continuing to investigate the circumstances."

Following Golbarnezhad‘s passing, the Iranian flag has been lowered to half-mast in the Paralympic Village.

The Paralympic Flag was also flown at half-mast at the Riocentro - Pavilion 6 venue, where Iran beat Bosnia and Herzegovina 3-1 in the sitting volleyball gold medal match today.

During tonight's Closing Ceremony, a moment of silence will be held.