Deloitte is being sued for failing to flag up more than $200 million of money laundering

A Dubai-based investment group is suing accounting firm Deloitte and Touche's Middle Eastern arm for failing to flag up money laundering at a now-defunct Lebanese bank.

Lebanese Canadian Bank paid over $100 million (£76 million) in 2011 to settle claims brought by US authorities that it was involved in laundering drug money and funnelling funds to Hezbollah and other militant organisations.

Deloitte and Touche declined to immediately comment.

Deloitte and Touche has been the bank's main auditor from 1995, and remains its auditor in liquidation.

LCB was shut down after the US Federal Bureau of Investigations and Drug Enforcement Administration actions and most of its assets were sold to Societe Generale.

Nest Investments Holdings, along with 10 other minority shareholders, is suing the accounting firm and Middle East managing partner Joseph El Fadl for negligence at the Dubai International Financial Centre.

The US Treasury said that LCB bank accounts were used "extensively by persons associated with international drug trafficking and money laundering" as a result of "management complicity," in a 2011 report. Nearly $230 million of illicit funds had passed through LCB's accounts while Deloitte and Touche were in charge of reviewing the bank's books.

"Deloitte and Touche Middle East failed in their duty as auditors because Mr El Fadl's team allowed their relationship with LCB senior management and majority shareholders to become compromised," the claimants said in an e-mailed statement. "DTME failed to adhere to Deloitte's high global standards on integrity, professionalism and objectivity."

Deloitte is not the only one to face legal action after failing to call out bad behaviour at a bank.

Global accounting firm PricewaterhouseCoopers is being sued for $5.5 billion (£4 billion) in a Florida court for failing to spot the fraud that led to the sixth largest banking collapse in US history.

Trustees for the Taylor Bean & Whitaker Mortgage Corporation, which went bankrupt in 2009, accused PwC of negligence in their audits of the bank's parent company, Colonial Bank. Top executives of TBW faked loan data for seven years starting in 2002, sending information on mortgages that either did not exist or had already been pledged to other investors to Colonial, the parent bank.