Police raided three properties and arrested four people on suspicion of neglecting a vulnerable adult.
Officers searched two addresses in Churchfield Road and Suttons Close in Outwell on Monday morning.
A further search was carried out in Lerowe Road, Wisbech, as part of the investigation.
Police arrested an 18-year-old man and a 68-year-old man, both from Churchfield Road, Outwell, a 30-year-old man and 53-year-old woman both of Suttons Close, Outwell.
All four have been released on police bail to return to King’s Lynn Police Investigation Centre on February 2.