Madonna has sparked fears her turbulent personal life is taking its toll on her health.

The '4 Minutes' singer - who is currently rehearsing for her forthcoming world tour - has reportedly fired two dancers, while her tour manager is allegedly threatening to quit due to her "spectacular mood" swings.

Madonna is reportedly at the centre of a sex tape scandal. A cameraman claims to have a video of Madonna and baseball player Alex Rodriguez romping on a sofa.

He is trying to sell the tape - allegedly shot with a hidden camera in an apartment owned by a friend of the cameraman which was used by the couple for secret liaisons - for $2 million.

Madonna's brother Christopher Ciccone insists the singer is still "a Catholic girl" and would never have an affair.

The 47-year-old author - whose book 'Life with My Sister Madonna' is causing controversy worldwide - is certain Madonna is not responsible for the breakdown of baseball player Alex Rodriguez's marriage, branding the rumors "absurd."

Alex Rodriguez allegedly confessed his love for Madonna at the beginning of this year.

The New York Yankees baseball star - whose close relationship with the singer is a factor in his recent split from wife Cynthia, her lawyers claim - told a pal he was besotted with Madonna as they had dinner at a restaurant in January, during which Alex spent most of the evening texting her.