Mr Pattharapong, or alias An Buriram, called for a probe into the building project located on the 5,083-rai land plot, which belongs to the State Railway of Thailand (SRT), reports the Bangkok Post.
The Chidchob family allegedly took a parcel of land to expand a race circuit and football stadium, while Anutin was accused of having a hand in a land grab in the forest park.
Mr Pattharapong said he petitioned the NACC after the Department of Lands (DoL) surveyed all land deeds in the park.
The survey, which was wrapped up last week, revealed the alleged encroachment.
Since the land is state-owned, any encroachment involving a political post-holder would constitute an ethical violation punishable by a lifetime ban from politics.
Mr Pattharapong said any role by Anutin and Mr Chaichanok in an encroachment would pose a danger, especially to Anutin, who is a caretaker deputy prime minister and caretaker interior minister, if he was to be re-appointed to the Cabinet posts.