The forward's deal is set to run out in the summer and the 18-year-old has generated interest in himself after starring for Dortmund this season as well as recently making his debut for Germany in a World Cup warm-up game prior to the tournament.
According to the Evening Standard, Moukoko's agent Patrick Williams has confirmed that the player has not signed a new deal with the club, amid strong interest from across Europe.
"I can confirm that we are not about to conclude a contract extension with Borussia Dortmund," Williams told Sky in Germany.
"I can also assure you that the numbers that are circulating are simply not correct and Youssoufa was never offered that much. But we are still in contact with Dortmund and will see what the next few days bring.
"A player like Youssoufa is interesting for every top club in the world. Especially when he is free and has a future in the German national team."
Clubs that are interested include Manchester United, Barcelona, Liverpool and Chelsea, all of whom will be vying for his signature if he becomes a free agent in the summer.
Currently, those teams will be able to strike a pre-agreement with the player from January if Dortmund cannot agree an extension.
This season has seen him become a more prominent figure in the Dortmund side, starting 12 of his 22 appearances so far, scoring six and assisting a further six times.