A multimillion pound film studios project dubbed Valleywood has faced more delays after rare dormice were found living on the site.
Dormice are a protected speices
A detailed search of the 317-acre site where the studios are to be built at Llanilid near Llanharan had to be carried out for the rodents.
A colony of the mice was found and conservationists are now working with the developers to secure their habitat.
Building work, which had been delayed, is expected to begin within weeks.
Scott Hand, a conservation officer with the Countryside Council for Wales said that surveys showed that dormice were found living on the site.
Because dormice are a protected species, steps have had to be taken to ensure that their habitat is preserved.
He said that the CCW are now working with the developers.
"CCW have since been working closely with the applicants to ensure that the needs of the dormice are integrated into the development at an early stage," he said.
"The most important steps taken to safeguard the dormice on site is the retention of as much habitat as possible and the improvement of habitat connectivity.
"Our aim is to integrate and safeguard the needs of internationally important biodiversity whilst acknowledging the need for economic growth in Wales," he added.
Dormice are protected under the Wildlife and Countryside Act 1981.
The delay in constructing the development is the latest in a series that Dragon International Studios, chaired by actor and director Lord Richard Attenborough has faced since the idea was put forward.
The studios will be built on this former opencast site
Discussions for the scheme began in 2001 but were initially opposed by the Welsh assembly, however these objections were withdrawn in October 2002 and an initial planning application was approved by Rhondda Cynon Taf Council in the December.
But in June 2003, the company behind the project, frustrated with delays in securing grants, threatened to change location of the studios from Llanilid to the former LG plant in Newport.
In January 2004, Lord Attenborough announced that building work on the studios would begin at the Llanilid site and hoped that the first phase of the scheme would be completed by the end of that year.
The developers were expected to begin work in September but fears that a colony of rare dormice was living on or near the site delayed the project.
A detailed search of the area was carried out which showed that there was a colony of dormice in the vicinity and so developers have had to work with the CCW to ensure that the rodents are kept safe during the development.
Building work is expected to begin within weeks.
The film studios project will include five silent stages, on outdoor street set and film production facilities and is expected to create 1,700 jobs.
Rhondda Cynon Taf confirmed that full planning had been granted for the development.