Two 14-year-old boys have been arrested in connection with the fire, which broke out on Thursday night.
Demolition work to flatten the remains of the burned-out structure has been underway today, with nearby residents being evacuated from their homes.
Pete Marquis, demolition specialist, said: "We've had quite a bit of a hold up today due to the possibility of a body being in it, so we've been stopped for three or four hours while the police and fire brigade put the dogs through (the site).
"Fortunately they've not found anything so we can now carry on.
"We're probably half a day behind, but that has to be done."