The government has been active in dealing with enforced disappearances, Foreign Ministry spokesman Sek Wannamethee said yesterday.
Mr Sek's comments came after the Office of the High Commissioner for Human Rights (OHCHR) on Wednesday urged the government to step up efforts to investigate the whereabouts of 82 people listed as missing.
In Geneva, the UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein, urged the government to take decisive efforts to investigate the whereabouts of at least 82 people listed as disappeared, including respected lawyer Somchai Neelapaijit who went missing nearly 12 years ago while defending people arrested under martial law in the restive South.
The suspects had accused the authorities of torturing them while in custody.
Mr Zeid also called on the government to criminalise enforced disappearance in its legislation, in line with international standards.
"All of the families of those who have disappeared have the right to know the truth regarding the disappearance of their kin, as well as any progress and the results of investigations," the High Commissioner said.
Among them is lawyer Somchai. On Dec 29 last year, the Supreme Court acquitted five police officers accused of involvement in his abduction and disappearance.
The wife and family of Muslim civil rights lawyer Somchai Neelapaijit have fought hard to keep his case alive. (File photo)
Mr Sek insisted Thai authorities have kept track of investigations of all missing people in the past 35 years. He said authorities are also working with the OHCHR in a bid to solve each case.
For Somchai, the investigation and the court's ruling were conducted in accordance with judicial process, in line with international standards, Mr Sek said.
Urging legislation criminalising enforced disappearance, Mr Zeid said: "There is a lack of an adequate legal and institutional framework for the victims and their families to seek justice in enforced disappearance cases in Thailand.
"I urge the Thai authorities to immediately ratify the International Convention for the Protection of All Persons from Enforced Disappearance."
Since 1980, the United Nations Working Group on Enforced or Involuntary Disappearances has recorded 82 cases of enforced disappearances in Thailand.
Mr Zeid said that despite pledges by Thai authorities to address human rights violations, the issue of enforced disappearances in which state officials have been implicated remains a serious concern.
The High Commissioner also expressed his concerns about another recent case, involving Porlajee Rakchongcharoen, a Karen human rights activist also known as "Billy", who disappeared in April 2014.
Before he disappeared, Billy had conflicts with a state official and was also fighting a case against this official in the Administrative Court, for which he was collecting evidence and witnesses. His case is similar to that of Somchai.
"The Thai authorities have a responsibility to ensure victims get all the help they need in finding their loved ones, to ensure the fair prosecution and punishment of perpetrators, and commit to stamping out the deplorable act of enforced disappearances," Mr Zeid said.