Police searching for Jessica Chapman and Holly Wells have cordoned off the house of caretaker Ian Huntley's father.
Officers are preparing to search the property and grounds in Littleport, 15 miles from Soham.
Meanwhile, police say the search at the college, school, and house of the arrested man, will continue.
A force spokesman said: "The search of the entire site will be the most comprehensive and detailed that is necessary and is likely to take days, and possibly over a week."