BEIJING -- The Supreme People's Procuratorate (SPP) on Tuesday announced it will directly oversee the "problematic vaccine" case, and urged prosecuting bodies at all levels to spare no efforts in their investigation.

The police recently discovered that improperly stored or expired vaccines, worth more than 570 million yuan ($88 million ) had been allegedly sold in more than 20 provincial-level regions since 2011.

Prosecutors across the country will work closely with local police and drug administration to uncover the manufacturing source, circulation channels and buyers of the inferior products.

The SPP also order a quick response mechanism to be established to facilitate information sharing, case details and case transfers.