Tourists at the Eiffel Tower may have been fiddled out of millions of euros in an alleged ticket scam that has been running for nearly 10 years, officials in Paris said.

More than 15 people working at France's most popular tourist attraction have been sacked, and a criminal investigation is underway.

The allegations concern staff deliberately crashing their ticketing computers as they were serving visitors, then selling the tickets which they did not register and pocketing the cash.

More than six million people go up the tower each year, with tickets costing from 3.7 euros ($3.2, �2.6) up to 9.9 euros ($8.6, �6) for a ticket to the top platform of the 324m structure.

Ticket 'irregularities'

Officials in Paris estimate the alleged fraud may have brought in up to four million euros ($3.5m, �2.4m) over the last decade.

The alleged scam came to light when the Societe Nouvelle d'Exploitation de la Tour Eiffel, the company that runs the tower, found irregularities in the cashiers' booths.

They said a review of records showed a big difference between the number of tickets issued and the number of tickets paid for through the registers.

The Eiffel Tower is believed to be the most popular paying tourist attraction in the world.

Built for the 1889 Universal Exhibition, it was the tallest building in the world at the time and a feat of iron construction.

Despite initial protests that it was ugly, it went on to become one of France's most cherished landmarks, and a world-famous symbol of its capital.