Three members of the United States House of Representatives have accused Switzerland's largest bank, UBS, of laundering money for the Cuban government.
 
They are calling for an investigation into transactions worth $3.9 billion (SFr4.9 billion) alleged to have been made between 1996 and 2003.

Ileana Ros-Lehtinen, congressional representative for the state of Florida, claims the Swiss bank carried out 1,900 transactions with the government of Cuban leader Fidel Castro over the seven-year period.

"We want to know the exact source of the money," said Alex Cruz, a spokesman for Ros-Lehtinen. "We are convinced that UBS employees laundered money."

UBS spokesman Christoph Meier said he had not been informed of any new investigation of the bank and rejected all accusations of money laundering.
 
Old for new
 
Ros-Lehtinen and her colleagues accuse UBS of buying old dollars from the Castro government and then crediting an account with new US banknotes.

The transactions would have been in violation of a US economic and financial embargo against Cuba, which has been in place since 1962.

At the time, UBS was one of a number of foreign banks contracted by the US Federal Reserve to exchange new dollar bills for worn-out notes being taken out of circulation.

But the contract specifically stated that the banks were not allowed to do business with countries under US sanctions.
 
 
"[These funds] could have stemmed from one of Castro's nefarious activities, such as drug trafficking." said Ileana Ros-Lehtinen, US congresswoman.

Suspicion
 
Ros-Lehtinen has also cast doubt on the Cuban government's explanation that the $3.9 billion flowed from tourism.

"Given the quantity we're dealing with, it is doubtful that the funds derived from tourism,” she said in a July 12 letter to Federal Reserve Chairman Alan Greenspan.

“Rather, [the money] could have stemmed from one of Castro's nefarious activities, such as drug trafficking.”

Ros-Lehtinen said the matter had been discussed during a meeting with UBS representatives on Thursday, but added that many questions remained unanswered.

Christine Whalton, spokeswoman for UBS in New York, declined to give any details about the meeting.
 
Trade violations
 
Two months ago UBS was fined $100 million after it was found to be in violation of the US embargo against Cuba and three other countries. Several employees were dismissed and others sanctioned.

The bank had agreed not to carry out dollar transactions with countries under a US trade embargo.

But following an internal investigation after queries from the Federal Reserve, UBS found dollars had been traded with the former Yugoslavia, Iran, Libya and Cuba.

It was also revealed that UBS employees had submitted false reports to the US authorities in a bid to conceal the transactions.

The Federal Reserve cancelled its contract with UBS last year and in May fined the bank for the violations.

swissinfo with agencies