The men were arrested at a farm in Wolmaransstad, North West police said on Thursday.
Police spokesperson Lieutenant-Colonel Pelonomi Makau said the policeman, who works in Gauteng, and his accomplices were arrested on Tuesday, after the police received a tip off about a suspicious Volkswagen Polo carrying male occupants.
Local farmers allegedly cornered the vehicle and the five men ran away.
"On arrival, the police found the Volkswagen Polo and a 24-year-old suspect already being apprehended by farmers. Two of the suspects who ran away handed themselves to the police at the scene."
The police searched the car and found a police blue light, handcuffs, forensic exhibit bags and two illegal firearms.
The other three were arrested on the N12 road while hitchhiking.
"A further probe revealed that the 52-year-old suspect is a police official working in the Gauteng province. He was allegedly found in possession of a police appointment certificate. During the arrest, the police managed to seize three firearms."
They were expected to appear in the Wolmaransstad Magistrate's Court later on Thursday.