Calcutta: The state fisheries department on Saturday collected fish samples from four wholesale markets in the city as retailers claimed supply from Andhra Pradesh had dipped and prices had gone up.

A further dip in supply from the southern state that accounts for almost 70 per cent of Rohu and Katla in Calcutta's markets could result in more price surge, retailers said.

A representative of fish traders from Andhra Pradesh told Metro that fishermen there had cut catches after Assam banned the state's supply on Thursday following the detection of formalin in fishes.

This also means supply to Calcutta is low and prices have spiked in most markets.

"Fishermen in Andhra Pradesh are worried of not getting the right price in view of Assam's decision," Mohammad Feazil, who handles the marketing of fishes from the southern state in Calcutta, said.

On Saturday, the Bengal fisheries department collected samples from wholesale markets in Howrah, Sealdah, Baghajatin and Patipukur.

Fish from other states reach these markets before being distributed across retailers in the city.

"Our mandate is to check if the fish samples have formalin. The tests will be conducted in our own laboratory," a department official said. "We will get the results in about three to four days."

Formalin is a preservative that can lead to cancer if consumed over a period of time. The chemical can also cause nausea and other ailments in the short term.

Metro visited a retail and a wholesale market in the city on Saturday.

Traders in both markets claimed the supply of Rohu and Katla from Andhra Pradesh had dipped and prices had gone up.

Ganesh Das, a retailer at Gariahat, said a whole Katla sold at Rs 250 a kg in the market on Saturday.

"For portions, the rate was Rs 320 a kg," Das said.

The going rate for a whole Rohu was Rs 150 a kg in the market. Both had sold roughly at Rs 15 less even four days ago, Das said.

Another retailer said prices would go up if the supply dipped further because of the formalin controversy.

In Sealdah, wholesalers had a similar thing to say. Prices went up about three or four days ago, many said.

"We have heard about Assam stopping supply from Andhra Pradesh. In such a situation we expected more supply to Calcutta's markets but that hasn't happened," a wholesaler at the New Baithakkhana market in Sealdah said.

"On the contrary, prices have gone up in the last three or four days," he said.

Apart from Rohu and Katla, the fisheries department collected samples of Bhola and Bombay Duck, two varieties that usually reach Calcutta from Diamond Harbour or Digha.

"We want to check if the local fishes are dipped in formalin," the department official said.