The government Thursday reiterated its defence against claims that last week's 20.9-million-baht chartered flight to the Asean-US defence meeting in Hawaii was exorbitant.
Operators of the website responsible for releasing the information about the flight are being sued for allegedly making false claims.
Government spokesman Sansern Kaewkamnerd held a press conference Thursday to clear up information about the trip led by Deputy Prime Minister Prawit Wongsuwon on a chartered Thai Airways International (THAI) flight.
Lt Gen Sansern said earlier information had misled the public.
The arrangement of the Hawaii trip conformed to regulations on procurement of supplies of the Prime Minister's Office that have been in effect since Aug 11, 2013, Lt Gen Sansern said.
The regulations require that the median price of a procurement worth more than 100,000 baht be announced to the public, Lt Gen Sansern said.
The fact that the government disclosed the median price of the Hawaii trip to the public was proof of its intention to maintain transparency, he said.
Chartering a flight is normally the last resort, and is chosen only when regular commercial flights and flights operated by military aircraft are not an ideal choice of transport.
Gen Prayut has taken two chartered flights to Milan and Russia since he came to power, while Gen Prawit travelled on the chartered flight to Hawaii for the first time since he took office, Lt Gen Sansern said.
As for the cost of the in-flight food and drink, which critics claimed was exorbitant, the spokesman explained the prices quoted by THAI were the maximum ones, adding that the bill would be based on what was actually consumed.
THAI president Charamporn Jotikasthira said the airline has filed a police complaint against the website "Yut Datcharit Prathet Thai", after it released a list of people alleged to have accompanied Gen Prawit on the trip.