The Defence Ministry said on Tuesday that it would take legal measures against any military members, past and present, who are found to be involved in selling Sor Dor 43 certificates.
Minister Sutin Klungsang was responding to claims by Wiroj Lakkhanaadisorn, a Move Forward Party (MFP) MP and chairman of the House committee on military affairs, regarding the sale of fake conscription certificates.
Normally, the Sor Dor 43 is issued by a conscription committee to those exempted from military service via an annual lot-drawing procedure.
A "Grade A" fake document complete with five official signatures is sold for up to 50,000 baht per copy, Mr Wiroj said in a Facebook post.
He said about 60,000 fake copies are sold yearly, amounting to 3 billion baht in fraud.
Mr Sutin said investigations into such claims and who is behind them are necessary.
He said legal and disciplinary punishment would be given to those found guilty of such corruption, no matter when it occurred.
Mr Sutin said retired service members involved in the sale of the fake certificates would have their pensions suspended.
He added that the Territorial Defence Command (TDC) has been working on this issue of fake certitudes on an ongoing basis, with arrests being made each year but not publicised.
When asked if the recent controversy regarding alleged evasion of conscription of two Move Forward MPs — Jirat Thongsuwan and Suphanat Meenchainan — was a part of an Information Operation (IO) by the military, Mr Sutin said he did not know.
He did say the ministry and related parties have been investigating the cases of the two MPs after receiving the complaints.
Prime Minister Srettha Thavisin had ordered those involved in the ongoing investigations not to use the information found during the probe to bully the opposition.
Meanwhile, ministry spokesman Jirayu Houngsub said that the Royal Thai Armed Forces will file a complaint with the police regarding the Sor Dor 43 sales network next week.