Kolkata, June 3 : As the Enforcement Directorate (ED) is all set to enter its next course of investigation in the multi- crore school recruitment case in West Bengal, the central probe agency will be adopting a twin-strategy. Sources said that the first part of the strategy is going for extremely calculated arrests only after ensuring that the chances of immediate bail for the accused are not present. A clear instruction has come from ED Director Sanjay Kumar Mishra who had held a meeting with top officials and legal brains of the agency in Kolkata on Friday. "Till not a single person arrested by our sleuths in this case has been granted bail. There is a clear instruction from our high command to maintain this trend in the coming days as well," an ED associate said. The second part of the strategy is to identify a couple of arrested accused who are willing to turn approvers in the case and examine the legal aspects of going ahead with the process. Two arrested middlemen -- Tapas Mondal and Niladri Ghosh -- have expressed their keenness to the central agency sleuths to turn approvers in the case. However, the sources said that the probe agency will take a final decision on this count only after going through detailed calculations to understand the legal implications on this count. As advised by Mishra, sources said that the ED officials investigating the matter will also constantly interact with their counterparts in the Central Bureau of Investigation and Income Tax Department, so that a coordinated approach by all the agencies will lead to making the cases more water-tight. However, legal brains point out that the process of an accused turning into an approver is an extremely lengthy process. According to senior counsel of the Calcutta High Court Kaushik Gupta, although Section 306 of CrPC has provisions on this count, the process is a bit complicated. "First the concerned accused has to make an official application to the investigative agency concerned expressing willingness to turn approvers. The investigating agency after examining the pros and cons of the development and also the probable future legal complexities arising out of the development might then seek the permission of the court the matter is being heard. The judge will take the final decision on this count after recording the reasons for doing so and other legal angles in the matter," Gupta explained. /IANS