Spanish police on Wednesday raided the Madrid branch of Industrial and Commercial Bank of China (ICBC) for laundry probe involving at least 40 million euros ($44.5 million), said the police in a statement. Police also warned that arrests were expected.

The bank is suspected of being used to "introduce into the financial system funds earned through the alleged crimes of smuggling, tax fraud and the violation of workers' rights, allowing the transfer of the funds to China in a way that appeared legal," the police statement said.

The investigation was a follow-up on a police operation in 2015, which targeted Chinese-organized gangs for importing large amount of goods without paying tax duties.

The crime group allegedly deposited the money earned to ICBC, who is now under probe for sending the money to China without checking their origins as required by law.

The bank’s attorney and executives responsible for the European regions are now on their way to the offices in Madrid, ICBC says. The bank says it will cooperate with the relevant investigation.