UniCredit, one of Italy’s largest banks, is the latest European financial institution to be investigated by US authorities over possible financial sanctions violations.

According to documents filed by the New York County District Attorney’s Office and the US Treasury Department’s Office of Foreign Assets Control (OFAC), UniCredit’s dealings raised suspicions seven months ago. A report in the UK’s Financial Times claims the subject of the investigation is the bank’s dealings with clients in Iran.

In an investment prospectus issued by UniCredit in January, the bank admitted the focus of the investigation regarded “certain, persons and/or entities believed to have engaged in sanctionable conduct”, indicating it believed the problematic dealings may be limited.

“The relevant UniCredit Group member also has disclosed to OFAC information that it has provided to the District Attorney’s office and is involved in ongoing discussions with these authorities and is cooperating fully.”

The latest revelation follows news that Royal Bank of Scotland is currently being investigated by US authorities for illegal dealings with Iran. UK banks HSBC, Standard Chartered, Lloyd’s Bank and Barclays have been fined more than $1bn in the past six months for doing business with the Islamic Republic and circumventing Western sanctions targeting the country’s nuclear development programme.