Details regarding the amount of private banking data being sent from the European Union to the U.S. Treasury Department are not forthcoming, raising concerns among European parliamentarians. Since Aug. 1, 2010, the E.U. has allowed European citizens' financial data to be transferred to the U.S. under the Terrorist Finance Tracking Agreement (also known as the 'Swift' agreement) if the U.S. can "clearly substantiate the necessity of the data" in combating terrorism. Europol, Europe's police force, has been given the task of verifying whether requests from the U.S. Treasury Department meet these criteria. To date, all requests have done so, according to Europol.However, despite confirming that 100 percent of requests have been complied with, Europol refused to say how many requests have been made. The organization said it had "recently comprehensively informed the European Parliament's Committee on Civil Liberties, Justice and Home Affairs about Europol's activities in the context of the implementation of the TFTP Agreement. This also included information on the requests verified so far."But this was denied by members of the committee. "Europol told us they were unable to give us any figures. That is remarkable, as we were given figures in previous reports on the transfer of SWIFT data (notably the February 2010 one). It basically makes it impossible to verify if the agreement is being applied correctly," said Dutch Member of Parliament (MEP) and committee member Sophie in 't Veld. "There is a clear reluctance within Europol to give full information. The atmosphere of secrecy and reluctance to be held accountable do not exactly contribute to a spirit of trust between the institutions, and the confidence that the agreement is at least implemented in accordance with the expectations of Parliament," she said."But the members of the committee -- as far as I can estimate -- did not feel informed to a satisfactory degree. Especially as far as the amount of transferred data is in question -- the information shared by Europol leaves us with two possible conclusions: either they do not share all available information with the Parliament or they truly do not have any clue. Both would be equally disturbing," added German MEP Alexander Alvaro, also on the civil liberties committee.In December, German representatives to the Council of Europe revealed that similar questions from the German data protection commissioner were not answered.Follow Jennifer on Twitter at @BrusselsGeek or email tips and comments to email@example.com.