Calcutta, Aug. 26 :    Calcutta, Aug. 26:  The CID has decided to 'formally approach' the Roy Burmans to seek their 'cooperation' in piecing together the jigsaw puzzle of the Khadim's kidnap case. 'Investigations have reached a crucial stage. And we do feel that the family is not divulging all details about the case. So, we will enforce the law if necessary,' a senior CID officer said on Sunday. 'The cooperation of Parthapratrim Roy Burman and his family is of vital importance, as the four abductors who came from Mumbai and their Calcutta-based contacts are still at large.' The Khadim's vice-chairman, according to sleuths, has 'not responded positively' to repeated requests from the CID to shed 'more light' on where he had been confined between July 25, when he was abducted from Tiljala, and August 2, the day he returned to his Salt Lake residence in a rickshaw, then a taxi. 'All he has told us is that the place was too dimly-lit for him to reconstruct the hideout... We are quite sure that he knows more than what he is telling us.' Admitting that the multi-agency probe - despite making 'good' progress with the arrest of 11 persons, including Swati Pal - had failed to round up the abductors and their local facilitators, a senior CID official said it was time the Roy Burmans helped them fill in the blanks. 'We need to know the identity of those who used to call up and threaten Roy Burman before the abduction. We also need information about Roy Burman's tours in India, especially about the people he would meet when he was in Mumbai.' CID inspector-general Partha Bhattacharya, meanwhile, categorically stated that there was no evidence yet about the involvement of any 'woman from Calcutta'. College student and model Panchali, who had been 'dragged into' the case by media reports, had 'no link, whatsoever' with Swati, Bhattacharya clarified. 'Besides our own probe into this angle, Swati, too, has never mentioned Panchali to us.' Panchali's family called on Bhattacharya on Saturday and wanted to know why her name had been been dragged into the case. 'It has all been very embarrassing,' Bhattacharya admitted. 'But all we can do is say that we have nothing against the girl .' The multi-agency probe team has failed to trace any record of Md Shafique's 'operations on Indian soil'. Officials, however, confirmed that Dubai-based Shafique had travelled to Abu Dhabi, Kuwait and Pakistan 'several times' in the past few months. 'He heads a gang which is now desperate to establish itself in India,' say officials. Abdul Rehman, Swati's 'husband' in Mumbai, went to Dubai twice before the abduction and stayed with Shafique.