The Department of Environment, Food and Rural Affairs has confirmed its inspectors have started a major investigation into allegations that growth inhibitors have been administered to a celebrity animal by his handlers.
The claims centre around a lamb known to millions of TV viewers as Shaun the Sheep, from the BBC children's series of the same name.
"We first became suspicious that something might be wrong, when my 5-year-old daughter asked me why Shaun hadn't grown up?" Senior investigator David Boucher explained.
"That got me thinking. It's highly unusual for a lamb not to have matured in 3 years. Normally, it only takes 12 months for a lamb to become a hogget, but Shaun is quite definitely still a juvenile lamb. Our working hypothesis is that Shaun is either a genetic freak or someone has been illegally administering some kind of growth inhibitor."
The BBC has declined to comment on the claims, and says it will co-operate fully with the DEFRA investigation. But it has declined to withdrawn the series from it'sa CBeebies channel.
However, the farmer who owns the land on which Shaun lives and who asked not to be named, has hit out at the allegations.
"I'm not admitting anything, but I have been asked to give Shaun and a second sheep, know as Timmy, special feed. I don't know what's in it - I don't ask too many questions when people are handing me huge amounts of money - but I'd know if anything dodgy was in it"
It's understood the investigation is in its early stages and an interim report won't be ready until the middle of autumn.