Thailand's attorney general on Friday expressed confidence that new evidence would persuade a German court to release a royal jet that was impounded at Munich Airport this month, according to dpa. "We have clear evidence that the airplane belongs to the prince and I believe we can convince the court of this," Attorney General Julasing Wasantsing said. Crown Prince Maha Vajiralongkorn's personal jet was impounded at Munich Airport on July 12 as part of an effort by the German firm Walter Bau AG to force the Thai government to compensate it for a contractual dispute dating back two decades. Last week, the Landshut court near Munich ruled that the plane could be released if the Thai government posted a 20-million-euro bond on it. Bangkok has refused to do so and plans to fight the case in Landshut at a trial scheduled in August. The timing of the impoundment of the Boeing 737 at Walter Bau's request has raised suspicion in Thailand, which held a general election on July 3 that brought to power the Pheu Thai party, whose de facto leader is fugitive former prime minister Thaksin Shinawatra. Shortly after the polls the German government decided to lift a travel ban on Thaksin that had been imposed in 2009. Thaksin faces a two-year jail sentence in Thailand on an abuse of power conviction. "Walter Bau's intentions are not pure," the Thai attorney general said, without elaborating. The German company has argued that the prince's private plane is actually state property, and could be seized to force Thailand to pay 36 million euros in compensation it was awarded by an international arbitration panel in Geneva in 2009. Thailand has refused to pay the money. "The international arbitration panel is not a court," Julasing said. Thailand is also trying to appeal a similar ruling made in a New York court in the same case earlier this year. The Walter Bau case has strained Thai-German ties, especially given Thai authorities' sensitivity about the royal family. The Thai Foreign Ministry on Thursday slammed the German embassy in Bangkok for issuing a statement over the weekend that called on the Thai government to pay Walter Bau the compensation. "His Royal Highness the Crown Prince is not party to the dispute, and neither is the government of the Federal Republic of Germany," the ministry's statement said. It added that the Thai government was "disappointed with the position and action the (German) government has shown in the issuance of the said press release by the German embassy to Thailand, which continued to unnecessarily and inappropriately refer to the impounding if the Royal aircraft that is personally owned by His Royal Highness the Crown Prince." The press release was reportedly removed from the embassy's website.