A further 1.5 million tickets were made available on May 11 in the second phase of the ballot system, but criticism has been levelled at Paris 2024 when it emerged that people had been allocated different athletics sessions.

According to French newspaper L’Equipe, several athletes have taken to social media to slam organisers for the mistake.

Among those include France’s European indoor 3,000 metres silver medallist Alice Finot, who described the error as "unacceptable" in a message on Instagram.

France’s middle-distance runner Jimmy Gressier highlighted examples of mistakes in the allocation process.

"Relatives told me that they had bought tickets for a particular discipline, for example the 5,000m, and with the calendar error they end up with a session that they did not want," Gressier wrote on Instagram.

"They wanted to see the 5,000m and will find themselves having to see the 200m or the javelin."

Paris 2024 organisers expect to generate nearly €1.4 billion (£1.2 billion/$1.5 billion) in ticketing sales, but they have faced criticism over the pricing, with one French poll finding that 82 per cent of those surveyed felt they were too expensive.

Athletics ticket prices range from as low as €24 (£21/$26) to as high as €980 (£850/$1,000). 

Estanguet admitted that the errors related to eight sessions of athletics competition after failing to update the online platform to purchase tickets.

"There are more than 760 sessions on sale in this second phase of ticketing," said Estanguet.

"On these eight athletics sessions, there was a programming error because the calendar has changed and it has not been updated.

"The online version was an earlier version of the International Federation.

"This is not a fight, the ticketing specialists know that it can happen.

"It is also written on the site that the programmes can be brought to evolve.

"It could still be the case, even if we don’t hope so because for us it’s a real challenge every time.

"We will treat this with great attention and rigour."

Estanguet dmitted he did not know how many people were affected by the mistake but vowed to fix the problem.

"We will write to them and find the best solution," he said. 

"We will inform all those concerned by these sessions.

"We apologise, we are really sorry.

"If we go into a bit of details, on what I can understand, for three sessions it’s rather good news because they will have more than they thought they were buying.

"But there are five sessions where there are actually less."

Paris 2024 announced earlier this week that one million tickets had been snapped up in the space of 48 hours, leaving 20 sports sold out including breaking.

Athletics, basketball, beach volleyball, football and tennis have been identified by organisers as the top five best-selling tickets.

An additional 3.5 million tickets are set to be put on sales in the third phase of the progress at the end of 2023.