Mumbai, Oct 28 (PTI) A Special Enquiry Team (SET) of the Narcotics Control Bureau has asked Prabhakar Sail, an independent witness who has alleged extortion attempt by NCB officials in the drug bust case involving Aryan Khan, to appear before it on Friday, an official release said.Deputy Director General of the NCB Gyaneshwar Singh on Thursday wrote a letter to the Mumbai Police commissioner asking the police to convey to Sail that he should appear before the SET, it said.Mumbai police, who are probing allegations of extortion attempt against NCB zonal director Sameer Wankhede and others following Aryan Khan"s arrest in the drug seizure case, has recorded Sail"s statement.The NCB team had asked Sail to join the probe on Thursday but despite efforts to contact him at his known addresses and telephone numbers, he could not be contacted, the release claimed.As the SET learnt that Mumbai police were recording his statement, it requested the city police commissioner to convey to Sail that he should appear before the SET at "any time after 10 am for recording his statement and submitting evidence," the release said. PTI DC KRK KRK KRK