Black-market cigarette makers in China appear to have found a novel way of ensuring maximum privacy - by disguising their illegal factory as a prison.
China's state-run Xinhua news agency reported that the factory had been unearthed in the southern province of Sichuan, with a sign on the gate reading: "Number 1 Block of the Xinkang Prison of Sichuan Province".
Officials from Xinkang Prison denied any part in the deception, according to Xinhua.
Xinhua said over 500 cartons of cigarettes and 117 tons of cut tobacco were found at the premises.
Four suspects and two lorries were captured during the police raid.
In keeping with the sign on the gate, workers had been treated like prisoners and had not been not allowed to leave the premises, Xinhua said.
Police said the underground factory manufactured about $30,000 worth of cigarettes in over 20 fake brands.
A police investigation has been launched.