A spokesman for Ba's management team rubbished Doorn's claims and said Ba "feels good" at Newcastle.
He said: "Armand Doorn is not Demba's agent. Alex Gontran is the only person who can speak on his behalf and Newcastle have not had an offer for him.
"Demba feels good at Newcastle, he has just started something there. There is a release clause in his contract but the figure will remain confidential.
"If a club wants to speak to Demba, then they must go to Newcastle first. We respect the process."