The curtain may have come down on what has been hailed as the 'greatest ever' Games, but the celebrations are far from over as fans across the globe came out in their thousands to welcome home their 2012 Olympic heroes.

From the Champs-Elysees in Paris to Piarco in the Caribbean islands of Trinidad and Tobago, the world's sporting stars were met with incredible scenes as supporters in their home nations flooded airports and city streets to honour their athletes' achievements at the London Games.

Athletes disembarking from their flights from London were showered with petals, mobbed by autograph hunters, and - in the case of one teenage gold medal winner - presented with a new house and a cheque for $155,000.

When javelin thrower Keshorn Walcott was promised the cheque when he landed in Trinidad and Tobago, along with a luxury home and roughly 20,000 square feet of land near his hometown.

His proud home nation is even planning to name a lighthouse and a Caribbean Airlines plane after the 19-year-old champion.

Prime Minister Kamla Persad-Bissessar lavished Walcott with gifts and praise on Monday as thousands of fans dressed in the national colours of red, black and white arrived at Piarco International Airport to greet the young athlete.

Monday was named a national holiday in honour of Walcott, who won the Olympic javelin title with a throw of 277 feet and six inches. His victory represented Trinidad's first Olympic gold in a field event and only its second overall.

The first one was won by Hasley Crawford in the 100 metre sprint in Montreal, 36 years ago.

'On behalf of the people of Trinidad & Tobago, we thank you, Keshorn, and may the Lord continue to bless you,'Persad-Bissessar shouted into a microphone over the chanting crowd.

Walcott, who is from the tiny Trinidadian farming village of Toco, looked slightly stunned by the outpouring of gratitude from his countrymen.

'I was proud to carry the flag of T&T and thanks to everyone for all the support and thanks to Mum and Dad, my brothers and sister,' said Walcott, who was the world junior champion in javelin before his big weekend win at the London Olympics.

Other dignitaries from countries all over the world turned out to greet the returning athletes, including Algeria's sports minister Hachemi Dijar, who was there to greet the country's only medal winner Taoufik Makhloufi when he landed back from the London games. Makhloufi won gold in the men's 1500m final.

Meanwhile Qatar's bronze medal winners received a warm welcome from Shiekh Joann bin Hamad bin Khalifa al-Thani, the son of the Emir of Qatar.

Nasser al-Attiyah took bronze in the skeet men's final in the shooting at London 2012, while high jumper Mutaz Essa Barshim also returned to Qatar decorated with a bronze medal.

Brazilian medal-winners touched down on home soil bearing the Olympic flag from London, making the start of four years of preparations ahead of the 2016 games in Rio de Janeiro.

Rio mayor Eduardo Paes waved the flag, which is emblazoned with the five Olympic rings, as he and other officials disembarked from their flight back from London.

Mr Paes said it was an 'important moment' for Rio and the country as a whole.

'I see the arrival of this Olympic flag as not the start, but the consolidation of an important process of transformation for the city of Rio de Janeiro,' he said.

'Rio is a city that spent the lion's share of its history, much more time than it should have, looking towards the past. I'm sure that this process of transformation, this turning toward the future, has been consolidated here.'

By Kerry Mcdermott