(contactmusic.com ) - Pop superstar Madonna has further fuelled reports she has gone under the knife after she was snapped hiding dark bruises around her eyes with a pair of sunglasses. The Hung Up hitmaker, 49, has previously refused to comment on whether she had had plastic surgery after she was photographed last month (Dec07) leaving a New York medical building with two black eyes. And now gossip sites are speculating the singer has undergone more cosmetic treatment, after emerging from her London home on Monday (21Jan08) with bruising to her eyes and cheek.