Chinese national arrested in Ginza for alleged mobile signal jamming and phishing scam

Police have arrested a 31-year-old Chinese national in Tokyo for his alleged involvement in a sophisticated mobile signal jamming and phishing operation. The suspect, identified as Yu Hai, a resident of Kita Ward, was arrested in flagrante delicto on November 7, 2026, at the Ginza 4-chome intersection in Chuo Ward. Officials say Yu is suspected of violating the Radio Law by using wireless equipment installed in a black vehicle to emit powerful radio waves that disrupted mobile communications.

The Mechanics of the Alleged Scam

According to police, the suspect allegedly used a vehicle-mounted device to create a localized signal disruption. This equipment was reported to cause mobile phones within at least a 500-meter radius to temporarily lose their connection to legitimate networks. During these outages, the device allegedly forced mobile phones to connect to an illegal, fake base station operated by the suspect.

Once the connection was hijacked, phishing short messages were sent to the users. These messages, written in Chinese, claimed there had been potential unauthorized use of a credit card. The Metropolitan Police Department is currently investigating whether these messages were used to steal credit card information from unsuspecting victims. During the investigation, police reported discovering large pieces of equipment inside the trunk of the suspect's vehicle. Despite the evidence, Yu has denied the charges, claiming that he does not own or use any wireless equipment.

Background and Investigation

The investigation into these activities appears to be the result of long-term monitoring by telecommunications providers and government agencies. Reports indicate that signal issues in Tokyo business districts have been occurring since approximately 2024, with users sometimes experiencing outages lasting between one and two hours. NTT Docomo conducted field investigations into these disruptions and identified the suspect before reporting the matter to the Ministry of Internal Affairs and Communications.

The Ministry of Internal Affairs and Communications had reportedly provided guidance to the suspect previously following reports of signal interference. The Metropolitan Police Department has received 18 consultations regarding suspicious messages and unauthorized charges over the last two years. Officials noted that these consultations primarily came from Chinese tourists. The estimated damages and losses resulting from these alleged activities are approximately 4 million yen.

Current Status of the Case

The Metropolitan Police Department is continuing its investigation into the suspect to determine the full extent of the credit card information theft. While the suspect maintains his innocence regarding the possession and use of the wireless equipment, authorities are focusing on the link between the signal disruptions and the subsequent phishing messages received by mobile users in the Ginza area. The case highlights the ongoing efforts by Japanese authorities to combat high-tech fraud targeting both residents and international visitors.

Glossary

• NTT Docomo — NTT Docomo is a telecommunications provider. The company conducts field investigations into mobile signal disruptions.