Gutter oil 'used to make antibiotics'
3 September 2012 Last updated at 17:45 BST
Food and drug safety authorities in China have told pharmaceutical firms to check their suppliers as they investigate reports that so called gutter oil is being used to make antibiotics.
The reprocessed kitchen waste, dredged from restaurant drains, has been implicated in a number of food safety scandals in the country.
The BBC's Martin Patience reports from Beijing.