Pop superstar Cher's representative has confirmed the singer is battling a deadly viral infection.

The Believe hitmaker, 68, has been spotted wearing a heart monitor, prompting reports suggesting an illness she suffered earlier this year (14) was far greater than imagined.

A source tells Closer magazine, "This viral infection she contracted scared everyone. It primarily affected her kidneys but played havoc with her entire body."

Now her rep confirms the singer has been wearing a heart monitor to "ensure that she continues her excellent recovery from the viral infection she had".

The spokesperson adds, "The doctors are very pleased with how well Cher's doing. She's out and about, exercising and rehearsing for her tour, which begins again in Texas in early November. She can't wait to get back out on the road."

Cher was forced to cancel tour dates after falling ill at the beginning of September (14), but she recently tweeted, "I'm strong. I'm happy to be alive. I want to thank all my fans for their good wishes, patience and prayers."