India’s anti-money laundering agency fined Standard Chartered Plc 1 billion rupees ($13.6 million) for breaking foreign exchange rules when it worked on the takeover of a local bank, marking one of the country’s biggest penalties imposed on an overseas lender.

An eight-year probe found that Standard Chartered violated the so-called foreign exchange management act which monitors offshore financial transactions when it worked with a group of investors to buy a stake in Tamilnad Mercantile Bank Ltd. in 2007, according to an August order from India’s enforcement agency that was seen by Bloomberg.

‘Senior officials at Standard Chartered saw an investment in TMB shares as an opportunity that might ripen into eventually larger ownership for the bank,’ Sushil Kumar, the enforcement agency’s special director, said in the order.

A representative for the British lender confirmed receipt of the order, adding that the bank was evaluating it and so unable to comment further.

Standard Chartered is India’s largest foreign bank by branches and also acted as a custodian for shares on the deal, according to the order. Tamilnad Mercantile was fined almost 170 million rupees for similar charges, the order said.