Hardy Rodenstock (born December 7, 1941 in Marienwerder (Kwidzyn), legal name Meinhard Gorke ) is a former publisher and manager of pop and Schlager music in Germany and is a prominent wine collector, connoisseur, and trader, with a special interest in old and rare wines. He became famous for his allegedly uncanny ability to track down old and very rare wines, and for arranging extravagant wine tastings featuring these wines. It has been alleged that Rodenstock is the perpetrator of an elaborate wine fraud. In 1992, a German court found that Rodenstock had "knowingly offered adulterated wine" for sale.

In 2005, U.S. art and wine collector Bill Koch, who had bought some of the bottles attributed to Thomas Jefferson, prepared to exhibit items from his collection at the Boston Museum of Fine Arts, including the Jefferson bottles. The museum asked for provenance of the items to be displayed. Koch had bought four bottles in 1988, Chateau Lafite and Branne-Mouton (present-day Chateau Mouton-Rothschild) of the 1784 and 1787 vintages, at a U.S. wine auction house (Chicago Wine Company) and a UK rare wine dealer (Farr Vintners), and paid a total of about 500,000 U.S. dollars for them. When Koch's staff couldn't find anything except Michael Broadbent's authentification of the bottles to confirm their provenance, the Thomas Jefferson Foundation at Monticello, Charlottesville, Virginia was contacted. The foundation's curator replied that based on Jefferson's records, the foundation didn't think that the bottles had been in the possession of Thomas Jefferson. Inquiries at Chicago Wine Company and Farr Vintners came up with the result that all four of Koch's bottles originated with Rodenstock.  After initial attempts at contacts with Rodenstock gave no significant results, Koch hired a retired Federal Bureau of Investigation (FBI) agent to form a team to start private investigations into Rodenstock's sales of wine. David Molyneux-Berry, former head of Sotheby's wine department was hired as a consultant, and several forensic investigations were conducted on the wines, bottles, and engravings; Koch alleges that the engravings were made with an electric power tool, which would not have been possible in the eighteenth century and would indicate modern forgery.  On August 31, 2006, Koch filed a civil lawsuit against Rodenstock (a.k.a. Gorke) in a New York federal court, claiming that he had been the victim of fraud. The reason that Rodenstock personally was named as defendant, rather than Chicago Wine Company or Farr Vintners, was that Koch claimed that Rodenstock had orchestrated an ongoing scheme to defraud wine collectors. Koch's lawsuit included many results from his team's forensic investigations. This lawsuit was then the subject of many legal turns during 2007 and 2008, primarily focused on procedural and statutory issues. A default judgment was entered against Rodenstock in May 2010. Rodenstock refused to participate in the trial.

Using a quote from the above article, answer the following question: When was this investigation launched?
On August 31, 2006, Koch filed a civil lawsuit against Rodenstock (a.k.a. Gorke) in a New York federal court,