A case has been registered against four people for allegedly trying to blackmail a city-based doctor and extort Rs 15 lakh from him, police said on Tuesday. The 45-year-old complainant has been working at a trauma care hospital in Jogeshwari for the past one year, said an official.

As part of his duties, he used to upload vaccination and fitness certificate details of Haj pilgrims on the Haj portal, he said. The accused — a woman and three men — allegedly met him at his office last week and showed him an old video clip in which he was seen sitting in a cafe and working on his laptop.