A former employee of the Rishon Tours travel agency - which was implicated in a 1991 police investigation into the funding of a flight for Ehud Olmert's wife and daughter, and is now at the center of the police investigation into flights for the prime minister's family members - told The Jerusalem Post on Sunday that "special arrangements" between the company and Olmert existed for many years. "It started while I was there, and it continued after I left," the former high-ranking employee said, referring to the irregular business relationship. The former employee refused to provide further details. In 1991, police suspected that Rishon Tours had been used to fund a private flight to New York for Aliza Olmert, the prime minister's wife, and his daughter Michal at a cost of $4,078. Detectives believed then that the flight was illegally paid for using campaign funds donated to the Likud for the 1988 general election, during which time Olmert had served as party treasurer. Then, as now, the National Fraud Unit led the investigation, and interrogated both Olmert and his secretary, Shula Zaken. Olmert told police Zaken was responsible for the travel arrangements, while Zaken said she had booked the flight in question through Rishon Tours because it "provides an excellent service." The case reached court, but Olmert was acquitted of the charges. Today, the travel agency's management are suspects in the fresh police investigation - opened after police said they uncovered evidence showing Olmert sought funding from multiple donors for the same trips, and, using a specially created fund at the travel agency, used the excess cash, estimated to total more than $100,000, to pay for personal flights for family members during his tenures as Jerusalem mayor and minister of industry, trade and labor. The travel agency, located in the heart of Rishon Lezion, demonstrated a business-as-usual air on Sunday, showing little sign of being at the focus of the most severe police investigation the prime minister has faced to date. About a dozen travel agents spoke to customers and phones rang frequently in what looked like another busy office day. Staff at the agency declined to be interviewed, saying they were forbidden to speak to the media. On Sunday, Haaretz published what it said were copies of two separate receipts from 2005 for Olmert's flights, sent by Rishon Tours to two organizations. The Israel Policy Forum, billed for $7,813, and the Soldiers Welfare Association, billed for $6,612, were both asked by Olmert to pay for the same flight to New York. The report said the receipts served to show how Olmert amassed the large funds at his private account at Rishon Tours. On Saturday evening, Channel 2 quoted unnamed senior law enforcement sources as saying that Olmert had tried his best to "play for time" and delay the interrogation session held Friday with National Fraud Unit detectives, and succeeded in delaying the meeting by a month. "Olmert was fully aware of the new allegations and was not surprised by them," the source said, describing Olmert's use of the funds as "classic fraud." Also on Sunday, Yediot Aharonot published a letter sent by National Fraud Unit head Lt.-Cmdr. Shlomi Ayalon to the prime minister's attorneys, in which he said Olmert's delaying tactics amounted to "a possible perversion of the course of the investigation. "With all due respect, even though this is the prime minister, the proper way to proceed is to have the investigating body set the date of the interrogation, rather than have it dictated by the party being investigated," Ayalon said. He also rejected a request by Olmert's attorneys to keep the details of the widened investigation away from public view. "In a properly functioning state, the existence of an investigation into the prime minister cannot be kept secret unless there are special circumstances, such as a court-imposed media ban, which do not exist in this case," Ayalon said. A number of law enforcement sources were quoted as saying that Aliza Olmert and the couple's children would be interrogated by police in the near future. The National Fraud Unit is said to be at an advanced stage in the investigation, and a former senior police source said he expected Olmert to be indicted within weeks.