Tony Bennett's publicists have insisted that the 88-year-old singer has not suffered a heart attack, and that the cancellation of a sold-out Royal Albert Hall show with Lady Gaga in London is due to flu and the fact that he has lost his voice.

Hyperactive Publicity said in a statement: "Unfortunately, Tony Bennett has come down with a flu virus which has prevented him from performing the second of two sold-out shows in London.

"Ticket holders are instructed to retain their tickets to this event pending more information."

It continued: "Fans who have purchased tickets online will be notified via the ticket outlets as soon as additional information is available."

Efforts are being made to reschedule the concert.