Specialist officers from Dyfed-Powys Police, along with others from other forces, have been searching the area in and around Machynlleth since the beginning of October.
The force says the search areas identified during the course of the investigation were completed on Friday.
47-year-old Mark Bridger has been charged with murder, abduction and intending to pervert the course of justice.
He denies all the charges.
More top news
A cooler night to come with possible showers in the northwest by the early hours!
There are calls for more to be done to help refugees and asylum seekers suffering with mental health issues.
We’re looking for people with an inspirational story to tell who’ve really made a difference to others through fundraising efforts.