CHRIS BROWN has denied he is headlining the musical tribute concert to MICHAEL JACKSON in Vienna this month, sparking fears from fans the ‘extravaganza' will be shelved.

Despite MJ's big brother JERMAINE holding a press conference to announce the gig Brown's people have denied he has even signed up.

Brown's spokesperson says, "Chris is not confirmed to perform or participate in any capacity for this show."

Jermaine also claimed RnB star MARY J BLIGE would be another of the headline acts, but her reps have confirmed she will be touring in Italy at the time.

So far, the ‘star-studded' event has (according to Jermaine) lined up Natalie Cole and Sister Sledge, as well as American boyband US5 - not exactly and A-list bill and fans fear the tribute will be shelved altogether.

And our sources tell us there's unrest within the Jackson camp about the whole thing with rumours that Jermaine is staging the gig against the wishes of matriarch KATHERINE JACKSON.

But the event's organiser George Kindel says, denied these claims, saying: "She will be there with Michael Jackson' s kids."

Hmmm, we'll see.