Standard Chartered acknowledged Tuesday it was being investigated by the US Department of Justice over claims that an Indonesian subsidiary had paid bribes to secure contracts.

The London-based, Asia-focused bank said in a statement that it had referred the matter to the "appropriate authorities" and launched its own review.

The Wall Street Journal newspaper said that an internal audit at Indonesian energy company Maxpower Group found evidence of possible bribery and US prosecutors were examining whether Standard Chartered was culpable for not stopping it.

"Standard Chartered takes very seriously allegations of impropriety in any of our private equity investments," the bank told AFP in a statement when asked about the report.

"We proactively referred this matter to the appropriate authorities and have conducted our own review.

"When we receive allegations of improper behaviour in an investee company, we pursue those allegations vigorously and act appropriately, including sharing information and cooperating fully with government authorities and addressing any issues of internal conduct and accountability."

The Department of Justice did not comment when contacted by AFP.

The Wall Street Journal said the Maxpower internal audit found that more than $750,000 in cash advances needed to be examined as possible bribes, while lawyers who reviewed the audit found indications that employees made inappropriate payments to Indonesian government officials between 2012 and 2015.

Standard Chartered began investing in Maxpower in 2012 and is the majority shareholder.

There was no immediate comment from Maxpower.

But a source close to the case told AFP the US authorities were indeed examining whether Standard Chartered, via its representatives on the Maxpower board, was aware of alleged bribes to win government contracts.

The investigation would also look at why the bank's alert procedures for spotting such matters had not been triggered.

But the probe will focus on whether Standard Chartered has violated the terms of its 2012 deferred prosecution agreements with the Department of Justice.

Standard Chartered paid $667 million in 2012 to settle charges it violated US sanctions by handling thousands of money transactions involving Iran, Myanmar, Libya and Sudan.

In August 2014, the bank was hit by US regulators with a US$300 million fine and restrictions on its dollar-clearing business for failing to detect possible money-laundering.