New Delhi, July 27: Food minister Ram Vilas Paswan today cited the example of bank interest to justify the rise in prices of food items over the past year while making it clear that middlemen and hoarders were the main problem.

Paswan claimed the only increase had been in the price of dal, as he replied to a short-duration discussion in the Rajya Sabha.

"Only dal price has increased. The states have to take action against the middlemen and traders," he said.

Leader of Opposition Ghulam Nabi Azad said the prices of all food items had skyrocketed and Paswan could face a "privilege motion" for misleading the House. "The minister says only dal price has increased. This is incorrect."

But Paswan came up with the bank interest analogy. "If the price of something was Rs 29 last year and increased to Rs 32 this year, what is the increase? Don't you get interest benefit of Rs 2/3?" he asked.

The link between "interest benefit" and price rise was not clear.

Unhappy with the reply, Congress MPs walked out.

Paswan said the price of arhar dal and urad dal had increased because of a fall in production. The international production of arhar has declined from 75 million tonnes in 2012 to 71 million tonnes this year. In India, 171 lakh tonnes of arhar dal was produced in 2014-15 against a demand for 236 lakh tonnes. In 2015-16, the production remained almost stable at 170 lakh tonnes, whereas the demand increased to 246 lakh tonnes. Therefore dal is being imported, he said.

"If the price is high, why cannot the states relax tax on dal, why cannot they take action against the hoarders, why cannot they directly import?" Paswan said.

Initially, however, Paswan had mentioned some items whose prices had increased. The price of sugar, for example, was Rs 29 a kilo this time last year but had increased to Rs 40, while tomato prices had gone up from Rs 29 to Rs 39.

Earlier, CPM leader Sitaram Yechury said the Centre was responsible to a large extent for the rise in prices of essential commodities, a major reason being the high price of fuel that increases the transport cost of goods.

While the international price of crude oil has fallen from $110 a barrel in May 2014 to around $40 now, the government has increased the excise duty on petroleum products by "nine times", he said.

Trinamul Congress leader Derek O'Brien asked the government to introduce air-conditioned vehicles to transport vegetables to stop them from rotting in transit.