One of Congress' premier watchdog panels is investigating Goldman Sachs' role in the subprime mortgage meltdown, including how the firm sold securities backed by risky home loans while it simultaneously bet that those bonds would lose value, people familiar with the inquiry said Friday.

The investigation is part of a broader examination by the Senate Permanent Subcommittee on Investigations into the roots of the economic crisis and whether financial institutions behaved improperly, said the individuals, who insisted upon anonymity because the matter is sensitive.