China's State Council has established a joint investigation team to look into the current vaccine trading scandal.

Officials from China's top drug regulator, securities regulator and health administration will head the investigation.

The State Council has also formed a supervision team to oversee the investigation.

The scandal erupted earlier this month after a pair of suspects were arrested in Shandong for selling black-market vaccines to hospitals.

Their arrest uncovered a ring of black-market vaccine sales across China, including the sale of improperly stored or expired vaccines in more than 20 provincial-level regions since 2011.

So far, more than 130 people have been detained in close to 70 different criminal cases connected to the scandal.