Italian prosecutors are seeking to indict 297 people and the Bank of China in connection with a massive money-laundering investigation.

The ANSA news agency reported Saturday that the suspects include four senior managers of the Chinese state bank's branch in Milan.

The Associated Press reported earlier this month that police in Florence discovered that more than 4.5 billion euros ($6.3 billion) in proceeds from counterfeiting, prostitution, labour exploitation and tax evasion had been sent to China in less than four years using a money-transfer service.

Nearly half that money was funnelled through the Bank of China, which in turn earned a commission, according to Italian investigative documents.

Investigators said they got nowhere when they tried to appeal to Chinese authorities for help. Once the money left Italy, it vanished behind China's great legal firewall.

Under Italy's justice system, a judge will consider the prosecutor's request and either order a trial or throw out the case. The judge's evaluation could take months before a decision is made.

In Italy, institutions as well as individuals can be ordered to stand trial.

ANSA said prosecutors alleged that the Bank of China didn't signal suspicious banking transactions to authorities.

The case involves operations carried out during the period from 2007-2010.

Prosecutors could not immediately be reached for comment as their offices were closed over the weekend.

According to prosecutors, at least some of the suspects used Mafia-like techniques, including intimidation, ANSA reported.