French security forces are vetting up to a million people before the Paris Olympics, including athletes and people living close to key infrastructure, the Interior Ministry has said.

Ahead of the Games on 26 July, all 10,500 athletes selected for the Paris Olympics and 4,400 for the Paralympics are being subjected to background checks, as will their coaches and medical staff, in addition to 26,000 accredited journalists.

"Nobody will be able to get accreditation from the organising committee unless they have been screened," said Julien Dufour, head of the Interior Ministry's security screening service, SNEAS.

"It's for everyone, except for spectators."

Of the 22,000 security agents and 45,000 volunteers, those with access to sensitive areas will be checked, while the 12,000 people chosen to take part in the torch relay have already been investigated.

A total of 13 people selected for the torch relay were rejected, including some who had committed drugs offences as well as a suspected Islamist.

With events set to take place around the French capital, including along the river Seine, Dufour said people living close to sensitive locations could also be vetted.

"You can assume there are investigations on people living in some areas," he said.