The National Anti-Corruption Commission (NACC) is investigating the landholdings of about 60 MPs on a case-by-case basis, secretary-general and spokesman Niwatchai Kasemmongkol said.
Mr Niwatchai made the remarks in response to calls for the NACC to speed up its probes against MPs in cases which could be similar to that of Pareena Kraikupt, the former Palang Pracharath (PPRP) MP for Ratchaburi banned from politics for life.
Ms Pareena was banned on April 7 by the Supreme Court for a serious violation of political ethics as an MP. It faulted her for wrongly possessing state land.
Mr Niwatchai said the NACC is investigating land ownership in the declaration of assets and liabilities submitted by some 50-60 MPs. However, this does mean all these cases will be the same as that of Ms Pareena and they must be considered on a case-by-case basis, he said.
"An inquiry panel set up by the NACC is investigating a few of the cases," he said.
"We have to work with other agencies to carry out on-site inspections of different landholdings, which is quite complicated. In the case of Ms Pareena, state agencies inspected the land and sent the information to the NACC, which made it easy for the NACC."
Asked whether MPs who are found guilty of illegally holding state land will be invariably deemed to have committed a violation of political ethics, he said the NACC will have to study the court ruling on Ms Pareena's case carefully.
Mr Niwatchai said the NACC is making progress in a probe on the ethical conduct of Deputy House Speaker and Bhumjaithai MP, Supachai Phosu, over landholding under a temporary landholding document Nor Sor 2.
In response to Mr Niwatchai's comments, Ms Pareena posted on Facebook on Monday that the court's ruling against her has made it clear that politicians could not occupy state land and doing so constituted a serious violation of the code of ethics.
She also called on the NACC to speed up its investigation into landholdings by the 60 MPs, without bias.
"The probe proceeds slowly as the NACC has already spent about a year on it and has not yet finished. Usually, a probe takes no more than 180 days. The NACC should hurry along and take action without discrimination," she wrote.
Meanwhile, activist Srisuwan Janya on Monday handed a letter to the NACC asking it to expedite a probe into 18 MPs over their alledged occupation of state land, particularly plots designated as Sor Por Kor land which is allocated to poor and landless farmers for agricultural use.
