Demolition workers Ken Cresswell, 57, and John Shaw, 61, both from Rotherham, South Yorkshire, have been missing since the building in Oxfordshire partially collapsed.
The body of Michael Collings, 53, who was also killed by the disaster, has been recovered from the wreckage.
The building was previously too unstable to be approached and a 50-metre exclusion zone was set up around the site.