A member of Indonesia's highest Islamic authority has said Muslims should stay away from an upcoming concert by American pop star Lady Gaga, who he said aimed to undermine the values of the world's largest Muslim country.

" (The concert is) intended to destroy the nation's morality, " said Indonesian Council of Ulema chairman Cholil Ridwan.

Cholil said Lady Gaga's sexy manner of dressing and dance should be considered "un-Islamic".

"She's from the West, and she often shows her private parts while performing, " he said.

He, however, added that he had never watched the singer perform and only heard of her "reputation" second-hand.

He said the 25, 000 fans who purchased tickets for the June 3 concert leg of the "Born This Way Ball" tour should return their tickets. The show sold out in around two hours when tickets went on sale March 10.