The 'Twittersphere' was sent into a frenzy earlier in the week when film actor Russell Crowe asked whether he should buy the Championship club or not.
The 50-year-old currently co-owns Australian rugby league side South Sydney Rabbitohs and the New Zealander was recently at Langtree Park for the World Club Challenge.
Reports had suggested that Massimo Cellino, owner of Leeds United, was looking to sell the club but Umbers has dismissed these rumours and insists the Italian is staying.
He said: "The club is not for sale nor do the Cellino family wish to sell and nor have we received any approaches contrary to reports in the press."