Porto were forced to react today over local reports suggesting Blues owner Roman Abramovich had agreed to pay the coach's escape clause.
The Dragons insist as yet no deal has been done for his departure.
"So far this club has not received any communication that this clause has been exercised, nor of the agreement of the coach that is desired," a Porto statement read.
Despite their determination to keep hold of Villas-Boas, president Pinto da Costa admitted the club could not prevent their manager from leaving should certain financial conditions be met.
"Villas-Boas has a contract and a clause of 15million euros," he confirmed.
"If someone deposits 15million euros into our account and he wants to go, we can not do anything because it is something that is contractually specified."
While there has as yet been no official comment from Chelsea, reports suggest a £4.4m-a-year salary is on the table for Villas-Boas, who could bring star striker Radamel Falcao to Stamford Bridge along with him.