Back in June, two nice young men rented three stalls opposite Thika police headquarters, saying they planned to open a bookshop.

Residents said they were friendly, but quiet and kept to themselves. No one would suspect their motives.

In the mornings, they brought in empty cartons and at night they removed “book” cartons, loaded them into a vehicle and drove off.

There was a little noise but everyone thought it was renovation.

This was the beginning of an elaborate, meticulously planned Hollywood movie-style heist of Sh50 million from KCB’s Thika town branch.

In fact, the men and possible others were drilling and digging 50-metre-long tunnel and trench under the bank and its strongroom.

The police were just 150 metres away and noticed nothing.

Over the weekend, the robbers broke through the floor, entered the vault and used oxy-acetylene torches to open safes.

Patiently, every night they loaded soil and sand from their excavation into book boxes and placed a few books on top of the contents.

The theft was discovered on Monday morning.

Three people — a woman and two men — were arrested on Monday, but they are not the main culprits.

Kiambu county commander Adiel Nyange on Monday said two of the arrested individuals hold keys to the stalls that had been rented by the robbers.

One is the caretaker of the exhibition shops at Thika City Friendly Stalls.

Nyange said police will “leave no stone unturned” to arrest the culprits.

“The three are in police custody and will assist in our investigations,” Nyange said.

He said the thieves dug a hole, approximately 10 feet deep and a trench 25 to 30 metres long directly to the bank’s strongroom.

Yesterday, bank activities returned to normal. Police have not ruled out the possibility some bank officials were involved.

“It’s too early to say whether it was an inside job,” Nyange said.

He was accompanied by Thika police chief Willy Simba and station boss Michael Otinya. Onyita said the Bank Anti-Fraud Unit and detectives would take charge.

-The Star/ John Kamau