Four women were arrested by two police cabins in Johannesburg.
Gauting Police spokesman Capt Qui Ali Mbele said that suspected people aged 27 to 45 were caught on Friday morning.
"Twelve women were arrested at 11.30 pm on the streets of Twist and Plain, and the police seized the counterfeit certificates from the police.
Two other men were arrested and nodded in the morning at 11.35 am on Wenderers Street. They stopped three foreign nationals who demanded a passport. One of the passengers of his passport said, "They wanted the R3000. Police rescued and seized suspects.
"The CBD in Johannesburg is now approaching the police to arrest the fake encounter police, which is damaging the form of police," the embassy warned.
The trial is on Monday at Johannesburg Magistrates' Court.