Cameroon midfielder Marc-Vivien Foe died of a heart problem when he collapsed during a Confederations Cup semi-final last month and no stimulants were found in his body, an autopsy showed on Monday.

The prosecutor in Lyon, the southern French city where 28-year-old Foe was carried off the pitch during Cameroon's 1-0 victory against Colombia on June 26, ruled out drugs or foul play and said he had found nothing abnormal.

"The death is from natural causes. No stimulant substances were found. The death was of cardiac origin," public prosecutor Xavier Richard said, announcing the autopsy result.

An initial autopsy had failed to determine the exact cause of Foe's death. Toxicology tests carried out as part of the autopsy had been handed to an expert in Geneva for analysis before a definitive conclusion was reached.

Foe is due to be buried with full official honours on Monday, following a mass at Cameroon capital Yaounde's cathedral. The burial will take place at the player's home.

Cameroon was plunged into grief by the sudden death of the midfielder, an unsung hero of the country's dominant position in African football over the last decade.

On Saturday, thousands of mournful fans lined the streets of Yaounde, waving palm fronds and branches as his body was brought home for burial.

Foe, who had 65 caps, featured at two World Cups, 1994 and 2002, and twice won the African Nations Cup, in 2000 and 2002.

He had played for French first division clubs RC Lens and Olympique Lyon, as well as West Ham United and Manchester City in England.

"He was a sportsman full of talent, generosity and humanity. We all miss him very dearly," said Kalkaba Malboum, head of the Cameroon's national Olympic committee and the African Athletics Federation.

Separately, FIFA said on Monday that all 64 dope tests conducted during last month's Confederations Cup had yielded negative results.