Buyers included German bank IKB Deutsche Industriebank AG – an early victim of the financial crisis that was rescued by the state-owned KfW development bank among others.
The Welt am Sonntag newspaper quoted Chancellor Angela Merkel's spokesman, UIrich Wilhelm, as saying that German regulator BaFin will ask the U.S. Securities and Exchange Commission for information.
"After a careful evaluation of the documents, we will examine legal steps," he said, according to the report.
There was no immediate confirmation from the government.
IKB spokeswoman Annette Littmann said the bank is aware of the charges filed by the SEC, but declined to comment further.
The SEC says IKB lost nearly all its $150 million investment.
IKB issued a profit warning in 2007, saying it had been hurt by U.S. subprime mortgage investments. IKB was sold in 2008 to Dallas-based Lone Star Funds.