The government on Friday sought an explanation from edible oil firms for the rise in retail prices of cooking oils despite advising them to ensure price stability amid the availability of adequate stocks imported at lower duties. On September 14, the Centre hiked the basic customs duty on various edible oils to support domestic oilseed prices, and subsequently on September 17 the food ministry convened a meeting with edible oil industry bodies to make sure that there was no rise in retail prices. "The industry has been asked to clarify and furnish reasons as to why the prices are showing upward trend since the announcement of import duty hike, despite the government's directions to maintain retail prices in the coming festival season," a senior food ministry official said on Friday. The ministry's assertion is that stocks imported at lower duties would easily last 45-50 days and therefore the processors should refrain from increasing maximum retail prices. Also, the price increase .