Food processing is all about adding water and salt and charging more. That’s what a food science prof told me a long time ago.

But usually that water is clean or potable.

Reuters reports China has held seven people in southern Guangdong province for injecting dirty pond water into lamb meat to swell its weight and raise its price, state television reported in the latest food scandal to hit the world’s second largest economy.

The suspects slaughtered up to 100 sheep per day at an illegal warehouse, pumping bacteria-ridden water into the meat before it was sold at markets, food stalls and restaurants in major cities such as Guangzhou and Foshan, China Central Television (CCTV) said in a three-minute report.

Authorities raided the illegal lamb meat abattoir in Guangdong at the end of December, finding around 30 carcasses injected with water, 335 live sheep, forged inspection stamps, and equipment to inject water into the meat, the report showed.

Each sheep was pumped with up to six kilograms of water just after being slaughtered, to add extra weight.