Santos sources allege that Chelsea approached the Brazilian superkid before he starred for his country against the USA in New York on Tuesday night.
The English club are expected to contest the allegation. Late Wednesday night, Stamford Bridge executives were unavailable for comment.
Star in the making: Neymar was in fine form during the clash with USA
Chelsea have been interested in the 18-year-old all summer - as first revealed by Sportsmail - but have seen at least one bid rejected.
Santos insist they will not do a deal for less than the £29.6million release clause in Neymar's contract.
However, transfer go-betweens claim a deal could be completed if the Barclays Premier League champions' bid tops £20m.
Having successfully overturned a UEFA transfer embargo last season following the controversial transfer of French attacking midfielder Gael Kakuta from Lens, Chelsea are expected to vigorously deny any wrongdoing.
When rejecting the opening offer from Chelsea last month, the Brazilian club said: 'Santos FC received an official offer from Chelsea for the economic rights of Neymar. President Luis Alvaro de Oliveira Ribeiro has sent a response to the English club thanking them for their interest and reiterating the fact that Santos FC have no interest in opening negotiations.'
Hand it to him: Neymar takes the praise after opening the scoring against USA
West Ham had a £12m bid for the player rejected last month in a move that would have been seen as a stepping stone to Stamford Bridge.
Neymar has scored 32 goals in 33 games this year and there was an outcry in Brazil when national coach Dunga overlooked him for the World Cup.
This week, having been called up by new coach Mano Menezes, who has taken over with a commitment to restore the Beautiful Game, Neymar delivered a star-studded performance on his full international debut against the USA , scoring the first goal after 29 minutes.
He said: 'Everyone was very comfortable playing together. Mano gave us a lot of freedom to do what we always do on the field and that helped a lot.'
While Santos continue to insist they will only do a deal if the release clause is met, they took the same position with promising striker Andre, who had a £41m buyout fee written into his contract, only to be sold to Dynamo Kiev for £6.5m in June.
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