Volunteer co-ordinator Wyn Humphreys said police have given their permission for a volunteer search to run in parallel to the police-led one.
He told BBC Radio Wales: "We're doing this off our own backs with the permission of the police.
"Every person going out has got to be accounted for," he added.
Detectives investigating the abduction of April Jones have until this afternoon to charge or release murder suspect Mark Bridger.
New photographs of missing five-year-old April Jones have been released by her family, as the search for her continues.
Police have been granted an additional 24 hours to question April Jones murder suspect Mark Bridger.