The tragic star's father Mitch Winehouse believes someone has unlawfully taken unreleased music, lyric books and letters belonging to the singer.
Only around 20 people - including family, friends, security and police - are said to have had access to the home in north London's Camden Square since Amy died on July 23.
However, to date, only two lyric books have been officially declared missing to police.
Ex-cabbie-turned-crooner Mitch, 60, is currently on a family holiday taken in an attempt to come to terms with losing his daughter, but he has vowed to find the cultprits on his return to London.
Other items Amy's management can't find include one of her favourite guitars and song lyrics penned for her third album.
A member of Amy's circle told today's Sun: 'This is such a sickening shock to the family. That someone would stoop so low. They can't get their heads around it.
Really pathetic !! :evil: