Nottingham Forest chief executive Mark Arthur says that striker Nathan Tyson has rejected a new deal and is leaving.
Tyson, who has been linked with Derby County, has previously said he wanted to stay and was waiting for an offer.
Arthur has told the club website they made it clear they would offer him a deal, but not until they knew which division they would be in next season.
However Arthur said: "Nathan's father [Len] has informed us he has rejected our contract offer."
Tyson, who has been with the Reds for five and a half years but is out of contract this summer, Tyson has said on Twitter that he will make no comment on his future while it remains unclear.
But BBC Radio Derby understands that the Rams are eager to sign the pacy 29-year-old frontman from their fierce rivals.
Arthur added: "Under normal circumstances, we would not be discussing matters like this in public but we feel there is a need to explain the situation.
"It seems clear from his father's press announcements that he is already negotiating with other clubs."