Kolkata, Jan 4 : Sujay Krishna Bhadra, a prime accused in the cash-for-school job case in West Bengal, returned to the state-run S.S.K.M. Medical College on Thursday after the Enforcement Directorate (ED) got his voice sampling test done at the Centre-run E.S.I. Hospital. After being taken to the E.S.I. Hospital late Wednesday evening following a surprise operation by the ED sleuths aided by central armed forces personnel, the process of his voice sampling test was completed by late Wednesday night. Sources said that he was taken to a special sound-proof room at the E.S.I. Hospital and there he was asked to repeat the same sentence a number of times which were recorded. Now the recordings will be matched with a call recording that ED sleuths secured from his mobile phone where he was asking someone to delete all records from his mobile phone. The entire process was completed on late Wednesday night and finally on early Thursday morning he returned to S.S.K.M. where he has been admitted since August last year soon after his bypass surgery. Getting the voice sampling test of Bhadra was not an easy task for ED following the reluctance of the S.S.K.M. authorities to allow them to conduct the test on medical grounds. Even the ED sleuths also complained to the Calcutta High Court accusing S.S.K.M. of deliberately trying to create hindrances for the voice sampling test. The counsel of the central agency had also challenged the medical reports furnished by the S.S.K.M. authorities by virtue of which the latter tried to halt the process of voice sampling. /IANS