NEW DELHI: Swiss bank UBS has refused to share any information with Enforcement Directorate on matters related to alleged money laundering and tax evasion by Pune based stud-farm owner Hasan Ali , a top ED official said today."We had a lot of difficulties, we have no hesitation to mention that the UBS, particularly in Hasan Ali Khan case, (have) just refused to share any information....They are not even prepared to share with us the name of the officials," said Balesh Kumar, Special Director, Enforcement Directorate during a workshop on money laundering. The ED officer said they have also made some specific requests in this case to the government."We are demanding from government blacklisting of banks for not sharing information (in this case). We have two demands, first blacklisting of such banks or if not banks, then at least the transactions," he added.The workshop was organised by BRICS Chamber of Commerce & Industry. Kumar further said that the bank asked the ED to obtain the information on Khan from their headquarters and the headquarters in Switzerland has told the agency to come through the letter rogatory route (a request from a court to a foreign court for some type of judicial assistance).In reply to a question, Kumar said in matters related with Khan, there are cases under Income Tax Act and Foreign Exchange Management Act (FEMA). "...the third case--this is the most serious--is a case under the Prevention of Money Laundering Act (PMLA)," Kumar said. He said the Special Investigation Team (SIT) set up after an order from the Supreme Court, is also looking at the investigations conducted by the ED under PMLA against Khan.Khan, a 60-year-old businessman, under arrest, came under scrutiny from multiple agencies under the Department of Revenue (DoR) and the Economic Offences Wing of the Mumbai police in 2007 first. These agencies had been probing him and his associates for various charges of money laundering, income tax evasion and violations of the Passport Act for the last seven years.Khan was slapped with an Income Tax notice demanding taxes over Rs 50,000 crore. However, there are no credible evidence with the tax authorities to further press their charges and ensure his conviction.