HSBC will apologise to the US Senate after an investigation claimed that the bank was being used to launder dirty money around the world. In a statement, Europe's largest bank, said it expected to be held accountable for what went wrong. HSBC will appear before the Senate at 09:30 local time (13:30 GMT). On Monday, a Senate report said that suspicious funds from countries including Mexico and Syria had passed through the bank. "We will apologise, acknowledge these mistakes, answer for our actions and give our absolute commitment to fixing what went wrong," HSBC said in a statement. The Senate report said large sums of drug money from Mexico had almost certainly been laundered through the bank, as well as questionable funds from the Cayman Islands, Iran and Saudi Arabia. Senator Carl Levin, chairman of the subcommittee that released the report, spoke of a "polluted" system that allowed black-market funds to move through the US banking system. "In an age of international terrorism, drug violence in our streets and on our borders, and organised crime, stopping illicit money flows that support those atrocities is a national security imperative," said Mr Levin. The report also concludes that the US bank regulator, the Office of the Comptroller of the Currency, failed to properly monitor HSBC. The report comes at a difficult time for the British banking sector, which is having its standards and practices scrutinised by regulators and policymakers. Critics say the current furore over the manipulation of the Libor inter-bank interest rate is the latest example of a banking system in need of fundamental reform. Mexico Cash According to the Senate committee, HSBC accepted more than $15 billion in cash from subsidiaries in Mexico, Russia and other countries at high risk of money laundering but failed to conduct any monitoring of these bulk cash transactions between mid-2006 and mid-2009. Furthermore, the report found that HSBC knew of lax anti-money laundering practices at its Mexican subsidiary HBMX which had dated back to its purchase in 2002. HBMX was warned, on at least two occasions, by Mexican authorities that drug money was probably being laundered through HBMX accounts. The report names individual cases such as that of Chinese-Mexican citizen, Zhenly Ye Gon. Mr Ye Gon, and his three Mexican pharmaceutical firms including Unimed Pharmaceutical were long-standing clients of HBMX. In 2007, a joint operation between the Mexican government and US Drug Enforcement Agency seized more than $205m in cash at Mr Ye Gon's residence - described as the largest drug-related cash seizure in history - along with $17m in Mexican pesos, firearms, and international wire transfer records. Mr Ye Gon is currently in a US prison awaiting extradition to Mexico on charges relating to the import, manufacture, and sale of chemicals to drug cartels for use in manufacturing methamphetamine. Miami office Many of HSBC's breaches of US anti-money laundering relate to its use of bearer share accounts. Under the rules for these accounts, ownership of shares and the income they incur can be passed from person to person in secrecy. HSBC's US subsidiary HBUS had opened more than 2,550 accounts for bearer share corporations. These businesses are commonly set up in tax havens such as the British Virgin Islands. Most of the bearer share accounts - some 1,670 - were opened at the Miami office of HBUS. At their peak, these Miami accounts held $2.6bn of assets and generated annual revenues of $26m. The report highlights the case of Miami Beach hotel developers, Mauricio Cohen Assor and Leon Cohen Levy. The father and son used HBUS accounts opened under the names Blue Ocean Finance Ltd. and Whitebury Shipping Time-Sharing Ltd. to help hide $150m in assets and $49m of income. The pair were jailed for 10 years for criminal tax fraud and filing false tax returns in 2010. 'Held accountable' The report into HSBC was released by the Senate Permanent Subcommittee on Investigations, a Congressional watchdog that looks at financial improprieties. The year-long inquiry, which included a review of 1.4 million documents and interviews with 75 HSBC officials and bank regulators, will be the focus of the hearing on Tuesday. Among the executives who will appear is HSBC's chief legal officer Stuart Levey, who joined the bank in January and was previously one of the top officials on terrorism and finance at the US Treasury Department. The head of the Office of the Comptroller of the Currency, Thomas Curry, will also testify. In a memo released ahead of the hearing, HSBC chief executive Stuart Gulliver said: "It is right that we will be held accountable and that we take responsibility for fixing what went wrong. "As well as answering the subcommittee's questions, we will explain the significant changes we have already made to strengthen our compliance and risk management infrastructure and culture," he said.