Organisers of the world's biggest film festival in Cannes have downplayed rumours there is a COVID-19 outbreak at the event, after James Bond star Lea Seydoux reportedly tested positive ahead of her appearance.

The event, which began on 6 July on the French Riviera, has so far welcomed stars such as Adam Driver and Matt Damon - despite the ongoing outbreak in the country.

Lea Seydoux, who is appearing in four films being showcased at the event, has become the first major name that will have to miss the festival after a positive COVID-19 test.

A spokesperson for Seydoux confirmed to industry outlet Variety that she had tested positive for the virus, despite being double-jabbed and asymptomatic, and will now quarantine in Paris.

It is not clear whether or not the actress will appear at the event or not, with sources telling Variety she is waiting for clearance from a doctor.

Among the films Seydoux is appearing in at the festival is the latest movie from Wes Anderson, The French Dispatch, which will get its world premiere this week and has been touted as a potential winner in the event's main competition.

Festival organisers have been forced to downplay rumours of an outbreak at the festival, with director Thierry Fremaux calling them "unfounded".

On Saturday he said: "Yesterday we did more than 3,000 tests (on festival-goers) and we have no positive cases.

"We are having to say this to show that the rumours of a Cannes cluster are unfounded."

Despite going ahead, the event has been significantly scaled back this year, with the usual glitzy showbiz parties fewer in number and the number of attendees falling.