Thiruvananthapuram, Even as authorities in Kerala claim that a vigil is on to prevent blackmarketing and profiteering by shopkeepers amid the nationwide lockdown due to coronavirus scare, price of essential items continue to rise in the coastal state.

In private shops, sugar price has increased by Rs 4, coconut oil by Rs 20, palm oil by Rs 15, and green gram by Rs 35.

Authorities claim around 500 cases were registered against private traders who jacked up prices of essential commodities.

Congress leader and Leader of Opposition Ramesh Chennithala claimed the government could be in cahoots with private traders as prices of essential items at state-owned Supplyco had gone up in less than a week.

"Look at the price list of Supplyco. Prices of many items have shot up. Compare the price lists of March 31 and April 6 -- price of green gram has gone up by Rs 8 per kg, green gram premium by Rs 10, rice by Rs 5 and chillies by Rs 3. If the state-run shops hike prices, then it would be free-for-all in the private sector. This has to be checked," said Chennithala.

"The accused were arrested but let off on bail. Now when the cases come up for trial it's the accused trader's responsibility to prove his case. He will have to produce his purchase bills," said a representative of traders.

"It has happened because cost of transportation has gone up and it reflects in the retail price of items," said a trader in the city's main market.

Another trader pointed out that as Kerala was a consumer state and dependent on huge supplies from neighbouring states, there was reduced supplies due to lockdown. There was also problem with free movement of various products.

"Maybe, things may change for the better as we are nearing the lockdown end. If a way is not found out, it's only natural that prices will rise," said another trader.