A top Croatian pop star "Severina Vuckovic" appealed to the public on Wednesday to return or destroy private pictures of her enjoying a lusty sex romp which appeared on the Internet this week. Severina Vuckovic told the daily Jutarnji List the pictures and an 11-minute video of her making love to an unidentified dark-haired man had been stolen from her private collection. They showed up on an internet site on Tuesday and immediately became the hottest news in the former Yugoslav republic, where 32-year-old Vuckovic had previously been an icon of righteous and religious modesty.