Amy Winehouse is probably turning in her grave over this one. Some chump broke into the late singer's London home and stole some of her personal belongings just days after she passed away. The worst part is that more than likely it was an inside job. At least 20 people -- family, friends, security and cops - have been in and out of the home since the 27-year-old mysteriously died. The Sun is reporting that the father of the Back to Black singer is devastated after someone broke into the house and stole personal letters, lyric books and unreleased music. Of course, these personal effects are probably worth a ton of money, not to mention the sentimental value attached to her work. The two lyric books were reported missing to police, but that's just the beginning. Among the other items are guitars and song lyrics she had been working on. One insider tells The Sun that everybody is in disbelief that someone could be so callous. Says the source, "This is such a sickening shock to the family. That someone would stoop so low. They can't get their heads around it. Mitch is livid. The family, record label and management are months away from deciding what to do with any unreleased music. For that to be taken out of their hands is horrible." Winehouse's father Mitch was seen giving away some of the singer's clothes to fans following her untimely death. And he's also offering the thief the opportunity to return the stuff before it gets ugly. The insider adds, "Mitch is willing to give whoever has stolen the items a chance to do the right thing and put them back so it doesn't have to get messy."