La Paz - The death of a Bolivian referee officiating a match at more than 4,000 meters has reopened the debate about the safety of playing football at such altitude.
Victor Hugo Hurtado collapsed while refereeing a Bolivian first division match in El Alto, at 4,090 meters, between the local side Always Ready and visitors Oriente Petrolero.
He had suffered a cardiac arrest and was stretchered from the field before being taken to hospital, where he died following a second heart-attack. He was just 32.
The El Alto municipal stadium is the highest in the world that is home to a professional football team, according to a banner displayed outside the ground.
It is more than 400 meters higher than the El Hernando Siles stadium (3,660 meters) in nearby La Paz that is used by the Bolivian national team.
Always Ready's club doctor Erick Koziner insisted altitude played no part in Hurtado's death.
"There was no pulmonary edema, that is the first thing observed in altitude sicknesses before it passes into the cardiac system," said Koziner after performing the autopsy.
Bolivia's football federation president Cesar Salinas told Diez.com website that "people inside and outside who don't like us will try to use this incident" against Bolivian football.
He insisted tests have previously "proved" playing at altitude "has no effect."
One of Hurtado's cousins, Orlando Herrera, told local media that the referee was used to altitude as he had previously lived in El Alto, once a sprawling La Paz suburb that has grown into it's own city.
Pedro Saucedo, head of Bolivia's refereeing commission, told Los Tiempos newspaper Hurtado had displayed "no signs of tiredness, nothing suspect" at half-time during the match. "He even told a joke."
Back in 2007, FIFA suspended all matches above 2,500m after some of Bolivia's rivals in South America complained that the minnows -- who have only qualified for the World Cup three times -- were gaining an unfair advantage playing in La Paz.
A month later a special exemption was made for the "Condor's Nest" in La Paz before the ban was overturned entirely a year later.
But that hasn't changed opinions. Two years ago, Brazil superstar Neymar posted a picture on Instagram of him and his teammates wearing oxygen masks ahead of a match against Bolivia.
"Inhuman to play in these conditions. Pitch, altitude, ball... everything bad," he wrote.
After the match, a 0-0 draw, Manchester City forward Gabriel Jesus said he "felt a little tired... it wasn't nice."
Bolivia were briefly banned from playing in La Paz in 1993 after Brazil lost a 40-year unbeaten record in World Cup qualifiers in a 2-0 defeat to the plucky minnows. Brazilian Joao Havelange was the president of world football's governing body, FIFA at the time.
And the subject came up again in 2009 after an Argentina side coached by Diego Maradona and starring Lionel Messi was humiliated 6-1 in a qualifier for the 2010 Word Cup.
Maradona was one of those to have criticized the FIFA ban two years earlier.
Whether playing at such an altitude is dangerous or not, there is no doubt that it provides Bolivia with an advantage.
Their record at home is leaps and bounds better than their efforts on their travels.
In World Cup 2018 qualifying, Bolivia lost every single away match, but at home they managed four wins and two draws from their nine games, even beating the mighty Argentina 2-0.
High-altitude pitches are not uncommon in the Andean country where Potosi's two teams Nacional and Real play at 3,990m in the Victor Agustin Ugarte stadium, while San Jose play at the Jesus Bermudez stadium in Oruro at 3,731m.
While this tragedy will undoubtedly heighten concerns about the safety of playing at such altitude, Bolivia's football federation has decided to act quickly to clear up any doubts.
"We have already taken the initiative to invite four specialists in the field to issue a very clinical and very medical report," said Salinas.