Dortmund signed Haaland in January last year and he has scored 43 goals in as many games for the Bundesliga giants since then.
While Dortmund are said to be keen on keeping the forward for one more season, there are suggestions that he could be sold in the summer if the club fail to qualify for the Champions League.
Manchester City have identified him as a long term target and Ole Gunnar Solskjaer still wants him at Manchester United after losing out to Dortmund to his signature last year.
Chelsea are also in the race and there are claims that they are increasingly confident of signing Haaland after holding talks with his camp through agents and intermediaries.
It has been suggested that Chelsea could be leading the race to sign him, but Fjortoft squashed the rumours.
He claimed that there is no truth to the speculation that Chelsea have their noses ahead in the race for Haaland.
The former striker took to Twitter and wrote: “I understand that reports on Chelsea being closer on Haaland than other clubs are wrong.”
Dortmund are expected to ask for in excess of £100m for Haaland if they are to sell him this summer.