"We do not monitor or block user content. User content is also encrypted, and cannot be viewed by LINE," the statement sent directly to dpa said.
On Friday, Deputy Prime Minister Prajin Juntong told reporters the Thai government had discussed the matter with LINE's executives based in Thailand, saying the company had agreed to set up a special team to monitor users' content.
However, the company told dpa Monday the Thai authorities need to go through diplomatic channels, such as the Thai embassy in Japan or the Japanese embassy in Thailand, and proceed according to international law.
"We ask the authorities seeking to obtain user data to make official requests through diplomatic channels and have so advised the Thai authorities," LINE added.
LINE is a social network application launched in Japan in 2011. It is popular in many Asian countries including Thailand, with up to 700 million users.
Earlier this month, Thai government officials sought cooperation with Internet giant Google in removing content likely breaching lese-majesty law on its subsidiary platform YouTube. Several YouTube videos have been taken down since then.
The government has shut down more than 30 websites per day as the nation mourns late His Majesty the King who died on October 13.