The arrested included Nigerian national Eric, who was nabbed from the Janakpuri Metro Station in Delhi following a tip-off by the other arrested accused.
The others arrested in the case include Haryana residents Bansi, Sher Singh and Sanjay, the spokesman said.
"Police personnel Krishan Kumar, Mandeep and Praveen have been arrested for accepting Rs 20,000 each as bribe in lieu of releasing the accused," the spokesman said.
"During interrogation, Eric revealed that he was involved in selling heroin and smack in several states, including Haryana. He had come to India in 2015 and had lost his passport and visa after arriving," the spokesman said.
The police have seized 60 gm heroin from the possession of the accused.
The spokesman said more arrests could be made in the case.
