A former worker at a security firm suspected of stealing ¥360 million from his employer's office in Saitama Prefecture was arrested Friday after he allegedly mailed the cash in four cardboard boxes to a post office box in Tokyo, prefectural police said.

Hiroki Ito, 28, was arrested in Tokyo after being on the run for three weeks, police said. Investigators believe he carefully planned the theft.

Police had said earlier that in-house security camera footage showed that Ito came to the office in the city of Misato on Sept. 4, packed up the cash he took from a secure room at the company and left with the boxes.

Police discovered that the boxes had been sent from the office to a post office box under Ito's name in Tokyo's Shibuya Ward. On the afternoon of Sept. 5, a man believed to be the suspect took the boxes there and left in a taxi. At around 1 p.m., he checked in to a hotel in the capital's Chuo Ward and left 2½ hours later. Empty boxes were later found in his room, police said.

Security footage from the hotel shows a man believed to be Ito carrying a backpack and a suitcase thought to be holding the cash, police said.