The abduction of Madeleine McCann may be linked to a trafficking network that sees children put on the market for $14,000, detectives have said.

Officers in France say Eastern European gangs are holding auctions in supermarket parking lots in Portugal and France. They have released details of the trade, as they believe it may be related to the four-year-old's disappearance, a Sky source said.

In one recent case, the mother of a baby boy was arrested for attempting to sell her baby North of Lisbon. In addition, two Romanian couples were arrested in a supermarket parking lot near Bordeaux while attempting to sell a girl.

Madeleine was snatched from her bed in her family's holiday flat in the Portuguese resort of Praia da Luz on May 3.

Shoppers in Monaco have reported seeing a girl of similar age and appearance to the missing child escaping abductors when they attempted to cut off her hair.

Experts have questioned, however, whether child traffickers or a childless couple are behind Madeleine's disappearance, as they would have taken her younger siblings, who were with her at the time.

Younger children are easier to abduct and smuggle, and are easier to 'mold,' experts told Sky.

Meanwhile, the number of reported sightings of Madeleine in Malta has risen to 14, with three new sightings on Saturday.

All 1,800 officers in Monaco have been given a picture of Madeleine while the airport and harbors are on high alert.

CCTV footage is also being checked to see if it shows the child being brought onto the island.