A man suspected to be the mastermind behind the robbery at an Equity Bank in Kayole estate on Saturday night has been described as "boring". His neighbours at the crime-prone Nairobi's Eastlands estate have said that the suspect was mostly a "boring, quiet guy", who liked to keep things to himself.

It has been revealed that for the two and a half months he lived next to the bank, the guy never used to interact with his neighbours in any way. The neighbours say that the door to his house was always under lock and key even when he was making a short trip to a nearby shop.

The "boring" man, said to be in his 30s, had rented a single room in a court sharing the rear wall with the bank, whose entrance faces the road in the opposite direction.

“He has been living here, even though I did not see him when he arrived. The premises are usually used for business but he lived there,” a businessman in an adjacent building was quoted saying.

The businessman added that he never saw anyone visit the quiet neighbour.

Police suspect the mysterious man had been drilling the shared wall, and when he finally created a hole that was big enough, he and his accomplices gained access to the bank, where they broke into the strongroom and made away with the money kept in two huge safes.

The unidentified man, who according to detectives is believed to have colluded with some bank staff to plan the theft, left his his room locked and went under the radar soon after the well-planned heist.

According to Nairobi County Police Commander Japheth Koome, the bank had not disclosed the exact amount of money carted from the Kayole branch, as it's officers were still harmonising their records. Nevertheless, it' estimated that more than Sh27 million were stolen.

As this happened, the security guard from the G4S was manning the bank’s entrance, oblivious of the theft that police suspect took more than 10 hours.