Kolkata, June 12 : Enforcement Directorate (ED) sleuths probing the multi-crore school recruitment case in West Bengal has summoned the son-in-law of Sujay Krishna Bhadra a.k.a. Kalighater Kaku (uncle of Kalighat) and son of private real estate promoter Ayan Sil for questioning in the matter. While Bhadra is in ED custody now, Sill is in judicial custody for their alleged involvement in the multi-crore school recruitment case. ED sent summons to both Bhadra's son-in-law and Sila's son on Monday. Sources said that the ED sleuths will question them about their huge assets in their names which are highly disproportionate to their income. The central agency sleuths suspect that there is every possibility that a part of the proceeds in the school recruitment case have been invested in their properties and assets. Sources said that under scanner of the ED officials is the source of investment in a petrol pump christened Shukla Service Centre adjacent to Durgapur Expressway where Sil's son is having a partnership. The central agency sleuths are expected to question him on funds he received to start this petrol pump. Meanwhile, the ED sleuths have identified a common modus operandi of Bhadra, Sil and Trinamool Congress legislator and former president of West Bengal Board of Primary Education Manik Bhattacharya. "The common thing between the three is that all of them used their close family members and the bank accounts in their names to divert the scam proceeds," an ED associate said. Bhattacharya, along with his son and wife, are currently in judicial custody for their alleged involvement in the school recruitment case. ED has summoned a Kolkata-based businessman who donated a high-value bungalow worth Rs six crore to a trust christened Banglar Bondu (friend of Bengal) which was run by Bhadra. The residence of the businessman whose name has surfaced in the matter is quite close to that of Bhadra at Behala in the southern outskirts of Kolkata. Bhadra will be presented at a special court of the Prevention of Money Laundering Act (PMLA) on June 14 at the end of his 14-day ED custody. /IANS