Cowell sings "tuneless" karaoke on cruise

Simon Cowell's singing has been described as "tuneless" and likened to "a pair of strangled hyenas", it has been revealed.

The 50-year-old is thought to have taken part in a karaoke night on his cruise holiday in the Mediterranean with guests including fiancée Mezhgan Hussainy, ex-girlfriend Sinitta and hypnotist Paul McKenna.

Cowell's vocal talents were reportedly mocked by McKenna, who pulled up his trousers to mimic the X Factor judge as he delivered his light-hearted criticism.

A source told The Mirror: "The gang have been having a fabulous holiday, and laughing so hard every night. Simon and Mezhgan have been getting on swimmingly and, with five couples on board, there have been quite a few candlelit dinners.

"Simon, by his own admission, is not pitch perfect - so Paul laid into his mate after a tuneless rendition of a Rat Pack number, and had everyone in stitches.

“As Si finished with a click of the fingers and a little hip thrust, Paul joked, ‘Frankly, Simon - it is Simon, right? - I’ve heard more tune from a pair of strangled hyenas. I’ve seen bananas displaying more personality than you.’”

However, Cowell has apparently had more luck competing in some of the other activities.

The source added: "During the day, they’ve had jet ski races and this is one thing Simon has excelled at.

"The group have been shimmying around the deck to Sinatra songs, drinking champagne. The whole voyage has been a rip-roaring success."

Katy Perry recently offered to organise Cowell's stag night with the help of Cheryl Cole.