The Asian Legal Resource Centre, in a press release purporting to be a letter to the United Nations Human Rights Council, said the Thai lese majeste laws prevent full freedom of speech in the country.
The group describes itself as a sister organisation of the Asian Human Rights Commission.
The lengthy statement, the seventh in a series opposing Thai lese majeste laws, said the group wants the UN to intervene with Thailand to call for release or bail for those awaiting trial or appeal on lese majeste charges.
In addition, the UN should "demand that the Government of Thailand revoke Article 112 of the Criminal Code and the 2007 Computer Crimes Act," the group said. In addition, the UNHRC should order its officials to monitor and publicise alleged constrictions of freedom of speech and "arbitrary arrests".
The ALRC provided no new information about lese majeste cases. But it said it "is gravely concerned about the effects of the ongoing entrenchment of the constriction of freedom of expression on human rights, justice, and the rule of law in Thailand".
The release detailed five current lese majeste cases, saying that a common feature of all was the denial of bail to the three suspects and two who are appealing their cases.
The group has previously claimed that lese majeste cases sometimes have weak evidence. The ALRC has said it believes the laws are a threat to human rights, and constitute "the active use of measures to constrict speech".