The state government said that special committees led by Civil Supplies commissioners have been constituted for checks in all districts.
Retailers holding over 10 tonnes and wholesalers stocking over 50 tonnes will be facing action.
The state government also sent a team to Nasik in Maharashtra to buy onions as part of its plan to control prices and regulate the quality of onions. The procured crop will be sold through co-operative societies.
According to reports, the price at the wholesale market in Koyambedu was about Rs 60 a kg and the retail price was Rs 80. In several places, it even hit Rs 90-100 a kg.