New Delhi, Sep 21 : The FinCEN files show that the world's biggest banks have allowed criminals to move "dirty money" around the globe. In total, these reports flagged more than $2 trillion in transactions, according to BuzzFeed News. The BBC reported that Russian oligarchs used banks to avoid sanctions and moved their money into the West. It is the latest in a string of leaks over the past five years that have exposed secret deals, money laundering and financial crime, a BBC report said. The FinCEN files are more than 2,500 documents, most of which were files that banks sent to the US authorities between 2000 and 2017. These documents are some of the international banking system's most closely guarded secrets. Banks use them to report suspicious behaviour but they are not proof of wrongdoing or crime. They were leaked to Buzzfeed News and shared with a group that brings together investigative journalists from around the world, which distributed them to 108 news organisations in 88 countries, including the BBC's Panorama programme. FinCEN is the US Financial Crimes Investigation Network. Concerns about transactions made in US dollars need to be sent to FinCEN, even if they took place outside the US. Suspicious activity reports, or SARs, are an example of how those concerns are recorded. A bank must fill in one of these reports if it is worried one of its clients might be up to no good. The report is sent to the authorities, BBC said. It has been revealed through these documents that HSBC allowed fraudsters to move millions of dollars even after it learned from US investigators that the scheme was a scam. JP Morgan allowed a company to move more than $1 billion through a London account without knowing who owned it. The bank later discovered the company might be owned by a mobster on the FBI's 10 Most Wanted list. There is also evidence that one of Russian President Vladimir Putin's closest associates used Barclays Bank in London to avoid sanctions meant to stop him. Accoridng to BBC, the UK is called a "higher risk jurisdiction" like Cyprus, according to the intelligence Division of FinCEN. That's because of the number of UK registered companies that appear in the SARs. Over 3,000 UK companies are named in the FinCEN files - more than any other country. Deutsche Bank moved money launderers' dirty money for organised crime, terrorists and drug traffickers. Standard Chartered moved cash for Arab Bank for more than a decade after clients' accounts at the Jordanian bank had been used in funding terrorism. There have been a number of big leaks of financial information in recent years, including 2017 Paradise Papers. The 2016 Panama Papers - Leaked documents from the law firm Mossack Fonseca showed more about how wealthy people are using offshore tax regimes, the BBC said. According to BuzzFeed News, some entities have been flagged numerous times in the FinCEN Files. Mayzus Financial Services, an online payment processing company that served clients involved in a bitcoin ring, sets the record, appearing as a subject of 36 SARs. Second is Kaloti Jewellery International, a Dubai-based precious metals company that was flagged as a subject in 34 separate SARs by eight different banks. More than 250 SARs reference people with addresses in the US, and more than 120 with addresses in Russia. The UK, China, Germany, the United Arab Emirates, Canada, and Ukraine were also common locations for people, each appearing in at least 20 reports, it said. /IANS