Kolkata, April 29 : The Central Bureau of Investigation (CBI) probing the multi-crore recruitment scam in West Bengal has started summoning the non-teaching staff in the 'Group C' category who have been identified as ineligible by West Bengal School Service Commission (WBSSC) and thereafter issued notification for the termination of their services. Sources said that the central agency in the first phase has summoned 10 'Group C' category staff whose services have already been terminated. They have been asked to be present at the office of the CBI's Anti-Corruption Branch (ACB) in Nizam Palace, Kolkata, in phases from May 1-3. The 10 people have been asked to carry all documents related to their appointments like admit cards for examinations and appointment letters among others. In the coming days, the sources added, more such candidates in the 'Group C' category will be summoned by the CBI sleuths and questioned. It is learnt that by questioning these candidates, the central agency want to have an idea about those involved in the money- chain paid for illegally procuring jobs. Last month, the WBSSC published a list of 842 non-teaching staff in the 'Group C' category of different state-run schools whose services were terminated following an order from a single-judge bench of the Calcutta High Court. CBI sleuths have already secured information about 8,163 OMR sheets that were allegedly tampered with to make room for ineligible candidates. Of the 8,163 OMR sheets, 6,304 in case of non-teaching staff -- 3,481 Group D posts and 2,823 Group C posts. In case of teaching staff, the total number of OMR sheets that were tampered with stands at 1,859, out of which 952 were for recruitment of secondary teachers while the remaining 907 were for recruitment of teachers at higher secondary level. /IANS