Kolkata, Oct 29 : Amid the recovery of banned narcotics consignment worth over Rs 20 crore in West Bengal in less than a month, the sleuths of the special task force (STF) suspect the different northeast region-based insurgent groups behind such rackets. State police sources said that there are several factors that add to the suspicion. 'Those arrested on this count during the last one month have confessed that the supply of these banned narcotics consignments mainly came from the different northeast states. However, those arrested so far have claimed that these consignments were handed over to them by the middlemen-handlers and they have absolutely no idea of the source outfits from where these consignments were actually coming,' said a senior official of the state police. This factor where the final-stage sellers are having no clues about the original source of supply makes the doubt about the involvement of northeast- based insurgent groups stronger. 'It is a known secret the northeast- based insurgents groups fund the different narcotics manufacturing rackets operating in the region. The manufacturers then circulate these high quality banned narcotics produced in the region to different peddlers throughout the country through intermediate carrier handlers. The typical phenomenon in this multi- chain trade is that barring very few top brains at the manufacturing level none other can interact with the financers, who are the representatives of the northeast based insurgent groups. This is evident in the recently busted rackets in Bengal, where the arrested do not have any clue about the financers,' the state police official said. The second point of suspicion on this count is the high and pure quality of narcotics consignments seized from the peddler arrested in West Bengal. State police sources said that although there are similar narcotics manufacturing bases in Bengal- adjacent Odisha, Bihar and even eastern part of Uttar Pradesh, the quality and purity of the consignments produced there are not as high as those produced in different northeastern states. /IANS