Subpoenas have been issued to another nine major banks in relation to the ongoing investigation into the manipulation of Libor.
Throughout August and September, a group of financiers including Bank of America, Credit Suisse and Lloyds Banking Group received notice of regulators' intention to analyze their potential involvement in this scandal, the Wall Street Journal reports.
This means the ongoing probe - which is being led by the Attorney offices of New York and Connecticut - has now included a total of 16 subpoenas and could lead to legal action being taken against a number of household names in the banking industry.
An insider with knowledge of the investigation told the news source that the banks involved include the majority of the members of the panel that helps set Libor.
Earlier this year, Barclays was ordered to pay fines of around $450 million for its involvement in the manipulation of the key interbank rate.
By Asim Shah