Thailand has blocked access to online petition site Change.org, after it hosted a petition calling for King Maha Vajiralongkorn to be declared persona non grata in Germany.
The Ministry of Digital Economy and Society said the petition’s contents violated Thailand’s Computer Crime Act.
King Vajiralongkorn has been criticised by protesters for spending much of his time in Germany.
The petition attracted nearly 130,000 signatures before the site was blocked.
It comes as Thailand is seeing some of its biggest pro-democracy protests in years.
Protesters are demanding amendments to the constitution, a new election and the resignation of Prime Minister Prayuth Chan-ocha.