The interbank association is responsible for approving medium-term notes and bills sold by companies, and most of those securities are held by banks.

WSJ: China Tightens Rules on Bond Issuance

The railway ministry, which is China's largest corporate-bond issuer, used all of last year's quota for long-dated bonds and also raised an additional 50 billion yuan via short-term bills and medium-term notes.

WSJ: China's Railway Ministry Gets Approval for Bonds

Among the alleged baits recently used to separate unwary investors from their funds: film deals, 19th-century railroad bonds, gold mines, iron mines, equipment leases, "medium-term notes, " greeting card manufacturing, a board game teaching investors how to get wealthy and even Mormon church financings.

FORBES: Fraud per capita

Of the medium-term structured notes that BarCap has managed since 2008, 20% went into precious metals.

FORBES