BEIJING, July 15 (Xinhua) -- Prosecutors are investigating dereliction of duty clues regarding food safety crimes and have vowed to crack down hard on such crimes.

A recent circular of the Supreme People's Procuratorate (SPP) orders procuratorates at various levels to increase the sensitivity of investigating job-related crimes regarding food safety and severely punish those involved.

Simply imposing fines instead of criminal penalties should be rectified, the circular says.

Prosecutors should pay attention to clues relating to "staff of administrative supervision, law enforcement and judicial organs accepting bribes, seeking personal gains and malpractice" in investigating food safety crimes, it says.