One of the accused officials, identified as head constable Raj Singh, has been arrested and his associates -- assistant sub-inspector Mukesh, head constable Harjinder, and one Vipin - are still at large, a senior police official said.
While Singh posted in south-west area is presently attending Police Training School for a course, the other two officials are posted in the vigilance wing of Delhi Police's west district. All three of them have been "dismissed" from service.
The students paid the officials Rs 28,000 and told them that they would soon pay another installment of Rs 50,000 in a few hours. But it won't be possible for them to pay the entire demanded amount.
Last evening, Singh and Vikas (an associate of the trio) came to south Delhi's Satya Niketan area to negotiate with the students. During the meeting near a Gurudwara there, two persons known to the students happened to be passing by. They enquired about the matter and the students told them everything, the official said.
"After investigation, a case of extortion and criminal conspiracy was registered," DCP (South) Ishwar Singh said. While Singh has been arrested, efforts are on to nab the other accused, he said.
Last week, three Delhi Police constables, including one posted in the Special Cell, were arrested under charge of extortion. The trio allegedly tried to extort Rs 20 lakh from the owner of a flat after barging into its premises in southwest Delhi's Dwarka area.