Initial investigation reveal that they entered India through Nepal border at Panitanki in North Bengal. As per their passports, they had visited Pakistan in 2018 and 2019.
The incidents of sickness due to contaminated water have been reported from ward number 73, said to be in the neighbourhood of CM Mamata Banerjee, as per reports.
Prior to this, CBI had carried out raids at multiple locations, including that of Mishra, who is believed to be a close aid of West Bengal Chief Minister, Mamta Banerjee's nephew Abhishek Banerjee.