The Director of criminal investigation George Kinoti was astonished after he visited Barclays Queensway branch and discovered fake golds stashed inside the safe that had fake currencies.
Kinoti spent three hours at the bank seeking to know how and why the management allowed individuals to store unsuspected cargo.
The bomb squad entered the vault and emerged with a safe deposit box weighing 70kg, which they said they would open at a secure location. They later reported that it contained fake gold.
Already two Kenyans has reported that they were conned Sh5.5 million.
Head of Flying Squad Musa Yego appealed to anyone else who had fallen victim to the gang to file a report in their Nairobi offices.
Those in custody include Erick Adede, who is the owner of the safe deposit box, Ahmed Shah, Elizabeth Muthoni and Irene Wairimu Kimani.
Police has said that the suspect are wider stream of international suspects who lure unsuspecting Kenyans with fake currency.