Several politicians formerly charged by the National Anti-Corruption Commission (NACC) have expressed doubts over the body's probe into Deputy Prime Minister Prawit Wongsuwon's luxury watch collection.

Numerous politicians have been caught by the NACC for submitting false asset lists over the years. However, all eyes now are on how the incumbent NACC will rule in Gen Prawit's case.

Pol Gen Watcharapol Prasarnrajkit, the NACC's president, was chosen to head the anti-graft agency in December, 2015 amid accusations he won the post with the backing of the regime.

It is reported he was a close aide of Pol Gen Patcharawat Wongsuwon, the deputy prime minister's younger brother, when he served as the police chief. After the 2014 coup, Pol Gen Watcharapol was also appointed secretary-general handling political affairs for Gen Prawit, when he became deputy prime minister.

Pol Gen Watcharapol says he is not worried about perceptions of partiality in the probe because he is working under NACC law.

Former education minister Mr Somsak Prissananantakul of the Chartthaipattana Party, said he is not hopeful of a just outcome as ruling figures wield absolute power. He indicated that their use of Section 44 means that politics is not at a normal setting.

He raised concerns as to why several independent organisations have had their members removed and replaced under the so-called "reset" measure, but this has not been applied to the incumbent NACC.

"The patronage system still prevails and that is the reason why some things fail to go in line with people's expectations.

"To what extent can we pin our hopes on the NACC's work? I don't think we can hope for much," Mr Somsak said.

He added that the NACC must be prepared to explain its findings.

"Time will tell as to whether the patronage system is still powerful," he said.

Meanwhile, Mr Jamras Wiangsong of the Pheu Thai Party said the NACC is likely to buy time until the current government leaves.

He said that Gen Prawit was likely to have been recommended by others to say he had borrowed the watches in the hope that it would put an end to the case. If Gen Prawit said he'd bought the watches himself, he would need to explain where the money came from. 

But by saying the watches were given to him by others, he could be found in breach of a rule which bars the holders of political positions from receiving gifts worth more than 3,000 baht.

"As for the incumbent NACC, I pin no hopes on it," Mr Jamras said

Mr Jamras and others have expressed doubts over the qualifications of some NACC members as set down in the 2017 consititution. However, the organic bill on the anti-graft agency enables all nine members to retain their positions despite these arguments.