Recent protests by maize farmers in several provinces have prompted the Commerce Ministry to investigate whether some crops were smuggled from neighbouring countries and sold to the government's pledging scheme.
The cabinet late October approved plans to buy up to 500,000 tonnes, or one third of local output, from corn farmers at 8.50 baht per kilogramme to support prices from Nov 1 to Dec 30. But officials say the quota was filled unusually quickly.
''It's pretty strange that despite the buying programme, prices of maize have yet to improve,'' said Yanyong Phuangrach, the director-general of the ministry's Internal Trade Department.
''There is thus a possibility certain crooked traders have smuggled products across the borders and used farmers' proxies to participate in the scheme.''
Domestic corn prices fell to 7.0 baht per kg in October from 8.50 baht in September and 12.50 baht in August. The current price is about 6.40 baht