Authorities are investigating whether traders at JPMorgan manipulated the market for Treasury securities and futures contracts, according to regulatory disclosures and people familiar with the matter.

The investigation shows that federal prosecutors and regulators continue to expand a campaign against an illicit practice known as spoofing, which has mainly focused on wily trading in derivatives. A move to scrutinise whether similar practices have affected the $17ton market for Treasury securities would open a new, and potentially more complicated, front in the war on spoofing.