Sources said the transfer orders of ED's Assistant Director Niranjan Singh in Jalandhar were issued last evening by the agency's headquarters here.
It is understood that he was transferred on the ground that many important cases like the Saradha and Rose Valley scams are being probed there and his services would be better used there.
Singh was the main investigator in the drugs money laundering case and he was also part of the team which recently questioned Punjab Revenue Minister Bikram Majithia in the same case in Jalandhar.
"The officer has been transferred to Kolkata. There is no connection with his transfer and the drugs case he was probing. It was felt his services were more required in Kolkata and the regional in-charge there had requested ED headquarters to send some good officers," sources in the agency said.
They said Singh is being sent on "an important" assignment in Kolkata and because of his good work he is being given a "challenging work".