The 27-year-old Grammy Award winner died last month after a long battle with drugs and alcohol.
Officials said they were awaiting the results of toxicology tests before they can determine the cause of her death.
Mitch Winehouse told Sky News about 20 people, including family, friends, security and police, have had access to her house since his daughter died.
The grieving father told the news agency he was trying to find out who took the items so he can recover them.
Shortly after the singer's death, Mitch Winehouse was seen distributing some of her clothing and accessories to fans milling about outside her house.