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 few showers at times but there'll be clear skies which will allow temperatures to tumble, which in turn means we'll see frost and ice!
From makeup to mechanics, video bloggers - or 'vloggers' - are broadcasting their knowledge to millions of eager consumers across the globe.
It's Christmas Jumper Day and Dyfed-Powys Police has dealt with a man caught stealing two Christmas jumpers.