He was 89.

Appointed Honorary Life President of the IOC when he stepped down as president in 2001, Samaranch was admitted to the Quiron clinic in his native Barcelona on Sunday with acute heart problems and passed away at 1325 local time.

He had died as a result of  "cardio-respiratory failure" hospital doctor Rafael Esteban said in a statement.

"I cannot find the words to express the distress of the Olympic Family," IOC President Jacques Rogge said.

"We have lost a great man, a mentor and a friend who dedicated his long and fulfilled life to the Olympics."

Sebastian Coe, the double Olympic 1500 metres champion and now chairman lof London 2012, said he had lost a friend and the world has lost an inspirational man.

"A man that challenged us all to fight for sport, its primacy and its autonomy, a fight he led fearlessly from the front creating an extraordinary sporting movement that reaches millions of people around the world," Coe said.

"He was quite simply the most intuitive leader I have ever met."

Samaranch stepped down in July 2001, 21 years after he had been elected as the IOC's seventh president, and was made life president when he handed power to Rogge.

 "I am personally deeply saddened by the death of the man who built up the Olympic Games of the modern era, a man who inspired me, and whose knowledge of sport was truly exceptional," Rogge said in a statement.

"Thanks to his extraordinary vision and talent, Samaranch was the architect of a strong and unified Olympic Movement.

"I can only pay tribute to his tremendous achievements and legacy, and praise his genuine devotion to the Olympic Movement and its values."

At last October's vote in Copenhagen on the host for the 2016 Games, Samaranch made an emotional appeal to IOC members to grant him a last favor and choose Madrid but they picked Rio de Janeiro instead.

"I know that I am very near the end of my time," Samaranch said during Madrid's final presentation.

Born on July 17 1920, Samaranch enjoyed success as a roller skater and led the Spanish team to the world title.

He pursued a career in sports politics in dictator Francisco Franco's fascist Spain and won a place on the IOC in 1966.

After Franco's death, he was appointed ambassador to the Soviet Union and the contacts he made there helped him succeed Lord Killanin as IOC president in 1980.

His body will lie at rest in the chapel at the Catalan Regional Government palace for members of the public to pay their respects between 1000 and 1500 tomorrow.

His coffin will then be carried on the shoulders of a group of athletes to the funeral at the nearby city cathedral.

He succeeded Lord Killanin as IOC president following the Moscow Games in 1980 and oversaw the abolition of amateurism at the Olympics, and the increasing value of TV and sponsorship rights.

Samaranch had many significant achievements, championing the representation of women in the IOC and overseeing the entry of the first women members in the 1980s.

He was also responsible for setting up the Court of Arbitration for Sport (CAS), and involving athletes in the IOC via the IOC Athletes' Commission.

"He made the IOC strong, financially strong," former committee vice president Lambis Nikolaou, who has been a member since 1986, told Reuters.

"He planned its expansion and was responsible for this unprecedented growth of the movement," he added.

"The last time I saw him was in Vancouver and his assistant told me Samaranch wanted to leave after the Games were over to go on a long trip to China or somewhere far away.

"That was Samaranch."

"He was just unstoppable."

He Zhenliang, the Honorary President of the Chinese Olympic Committe, was deeply saddened by the death of Samaranch, whom he worked with for 20 years since he was elected to the IOC in 1981.

"The Olympic Movement lost a great leader, China lost a close friend and I lost a very close friend and an old brother," said the 80-year-old He.

It was during Samaranch's reign that China returned to the Olympics in 1984 after a 32-year absence.

And awarding the 2008 Olympics to Beijing was widely regarded as one of Samaranch's final legacies at the end of his Olympic reign in 2001.

"Samaranch has made great efforts to help China regain the positions in IOC and other international sports organisations," said He.

"He also made great efforts to support China to have a bigger say in the international sports arena."

The United States also paid their tribues.

"It is with great sadness that we learned the news today about Juan Antonio Samaranch," said Larry Probst, the President of the United States Olympic Committe (USOC). 

"President Samaranch was a great supporter of the Olympic Movement in the United States, and in particular was a great supporter of our athletes.
 
"We salute this special man's preeminent place in the history of the Olympic Movement. 

"Our hearts go out to his family, his friends, the people of Spain and most importantly to all the athletes whose lives he made better."