LUCKNOW, Jan. 31 -- The Lucknow police arrested a key figure connected to a disputed nikahnama (Islamic marriage document) in Pilibhit district as the investigation into allegations of sexual exploitation and forced religious conversion involving a suspended resident doctor linked to King George's Medical University (KGMU) gathered pace, officials said on Friday. Shariq Khan, a resident of Neuria in Pilibhit, was taken into custody on Thursday night and arrested on Friday after days of surveillance, said Nagesh Upadhyay, the inspector incharge of Chowk police station. Khan, an accused in the FIR, was arrested after his involvement was established during the investigation, the police officer added. Khan's name surfaced during the interrogation of prime accused Dr Rameezuddin Nayak alias Rameez Malik, who is currently in jail in connection with the case, police sources said. Officials said Khan signed the nikahnama as a witness and is now being questioned about the circumstances under which the marriage ceremony was conducted and the sequence of events leading up to it. The case was registered at Chowk police station in Lucknow on December 23 following a complaint by a woman doctor from West Bengal, who had been posted in the pathology department. She accused Dr Malik of sexual exploitation and coercing her into religious conversion and marriage. During the course of the investigation, a second woman doctor from Agra made similar allegations, claiming she too was pressured into conversion and marriage. Based on these statements, police named two additional accused - Qazi Zahid, a cleric from Neuria in Pilibhit, and Shariq Khan, listed as a witness in the marriage document. According to police officials, the alleged marriage ceremony was solemnised by a cleric from the Filkhana locality under Sadar Kotwali limits in Pilibhit, with Khan present as a witness. Authorities are now examining whether due legal procedures were followed and whether any coercion, misrepresentation, or concealment of identity was involved. "The authenticity of the nikahnama, the role of those present, and the circumstances under which it was executed are key areas of investigation," a police official said. Police said the investigation has extended beyond Uttar Pradesh. Teams have carried out searches in Uttarakhand and other locations to trace individuals allegedly linked to the case and to gather documentary and digital evidence. Dr Malik's ancestral home is in Neuria, Pilibhit. His parents, Saleemuddin and Khateja, who had been living in Khatima, Uttarakhand, were arrested on January 5. Malik was arrested and remanded in judicial custody this month. He was also suspended by KGMU. After a court issued a non-bailable warrant, a Lucknow police team reached Pilibhit on Thursday. With assistance from the local Kotwali police, they conducted a raid in the Punjabhiyan locality and detained Shariq Khan. Officials are also analysing digital communications, travel history, and possible financial links between the accused and others connected to the alleged marriage and conversion process....