US authorities are investigating London-based Standard Chartered for potential US sanctions violations connected to its banking for Iranian-controlled entities in Dubai, according to people familiar with the probe.

The latest investigation involving the bank is based, in part, from evidence that emerged during a separate probe of BNP Paribas, the French bank that pleaded guilty this summer to charges related to sanctions-busting and agreed to pay $8.9 billion in penalties, the people said.

During the course of the BNP case, US federal and state investigators received evidence the French bank had done business with a Dubai-registered corporation that was a front for an Iranian entity, one source said. Investigators also learned that the company used to have an account with Standard Chartered, according to the source.

Such an account would have been covered by US sanctions laws that ban dealings with Iran because activity in the account involved US dollar transactions.

The sources did not want to be identified because the probe is ongoing and its ultimate outcome unknown.

Spokesmen for the Manhattan District Attorney and U.S. Department of Justice, which are among the authorities investigating, declined comment, as did the New York Department of Financial Services, which oversees the bank's branch in the state. A spokesman for Standard Chartered also declined comment on the probe.

The New York Times reported on Wednesday that prosecutors were taking a new look at Standard Chartered over possible sanctions violations, but the focus of the investigation was not revealed.

News of the investigation comes on top of the bank's major settlements with authorities over U.S. sanctions-related violations in 2012, and again this year.

Standard Chartered in 2012 paid $667 million to US authorities and entered into deferred prosecution agreements with the Manhattan District Attorney and US Department of Justice over violations stemming from Iran and other sanctioned countries.

In August of this year, New York's banking regulator fined Standard Chartered another $300 million after a monitor appointed in 2012 uncovered shortcomings in the bank's surveillance systems that caused a "significant number of potentially high-risk transactions" to go undetected, according to a consent order.

The new investigation, sources said, goes beyond the major findings in the 2012 agreements, in which Standard Chartered accepted responsibility for stripping information on wire transfers to the U.S. so they wouldn't be detectable as payments connected to Iran or other sanctioned entities.

The sources said the account at Standard Chartered discovered through the BNP probe was one example of potential additional violations, and that authorities are looking at other problematic small and medium-sized business accounts in Dubai that may have been controlled by Iran.

The investigation is "very active" but not at the point of discussing a resolution, one of the sources said.-Reuters