A woman in her 70s became the first confirmed victim of a scam concerning the My Number identification code system, the Consumer Affairs Agency said Tuesday.

The woman, who lives in the southern Kanto region, has been defrauded of several million yen, with perpetrators pretending to be government officials, the agency said.

The My Number system, which was introduced last week and under which every resident in the nation will be assigned a 12-digit ID number, can evidently be abused by fraudsters.

According to the agency, the woman received a phone call sometime last month or before that from a person claiming to be an employee of a government-affiliated organization and was told a fake ID number.

A man then called again, asking for donations to a public organization and for the woman to share her My Number ID. The woman agreed, thinking it was a genuine donation, the agency said.

Then, another caller threatened the victim, saying it is a crime to give individual ID numbers to a third party. The caller demanded money to "fix records," and the woman paid, once by postal mail and another time in person.

Local consumer affairs centers around the country have received some 20 requests for consultations from people regarding suspicious phone calls, email messages and letters over the My Number system. The agency said it will never ask for details of bank accounts or financial assets of individuals in relation to the start of the ID system, and urges consumers never to comply with such requests.