Sao Paulo president Juvenal Juvencio has no intention of selling Brazil star Lucas Moura, Brazilian daily Globo reported.
Despite Sir Alex Ferguson revealing that both clubs have agreed a £26 million deal for the Brazil wonderkid, it is not a done deal yet.
Moura's representative has now claimed that the proposed move is on the rocks as the Red Devils are refusing to meet Sao Paulo's asking price for the young winger, according to the Daily Mirror.
The player's agent, Wagner Ribeiro, has warned United they have little chance of prising the teenager away from South America unless they match Sao Paulo's valuation, which is significantly higher.
Ribeiro told www.uol.com.br: "They have reached their limit, they will not offer anything more. He will not leave. He is happy in Sao Paulo.
"This matter has to be terminated, there is no possibility of him leaving now.
"Manchester United made an offer which was refused, and will not do another because they came up to their limit."
Ferguson, who has already added midfielders Shinji Kagawa and Nick Powell to his squad this summer, admitted Lucas is among his remaining targets during the Red Devils' pre-season trip to China.
He told a press conference: "We have shown an interest, but until such time a we get a deal agreed, we can't say he's our player."