Those arrested include former district police chief Jammu Manohar Singh, station house officer Sultan Mirza and sub-inspector Satnam Singh.
The arrest followed investigation by the SIT headed by deputy inspector general of police Jammu-Kathua range, Farooq Ahmad Khan, constituted to probe the murder of Amandeep Singh, son of a former opposition People's Democratic Party legislator.
The SIT had found that the weapon of murder, a pistol had been substituted to favour the main accused in the case -- son of a Jammu-based businessman.
Earlier, the SIT arrested deputy director of the Forensic Science Laboratory and recovered 3.5 lakh rupees from his residence.
It is believed that an astronomical sum of money had changed hands to favour the main accused.