A 38-year-old Vietnamese woman was arrested for allegedly printing counterfeit NT$1,000 notes – some of which were circulating in parts of southern Taiwan – while a 53-year-old local man accused of being her accomplice was apprehended on Monday.

The woman surnamed Nguyen and the Taiwanese man surnamed Chuang were arrested at a rented home unit in Chiayi City, according to a media briefing by Yunlin County Police Bureau on Tuesday, The Liberty Times reported.

Officers recovered around NT$2.6 million (US$89,022) worth of counterfeit NT$1,000 notes at the scene, along with templates and tools used for the forgery.

However, fake notes with a total value of NT$350,000 (US$11,905) were believed to have gone into circulation.

A preliminary investigation found that the woman was a repeat offender allegedly skilled at making counterfeit notes.

In 2016, Nguyen was arrested for assisting her former boyfriend surnamed Chang, seen as the prime offender, now serving a term in jail for printing fake money.

Chuang, who served as president of a local charity group for physically challenged people, told police he was only the landlord who rented the unit to Nguyen. He claimed to have no idea what she was doing there.

Citizens are advised to pay special attention to NT$1,000 notes printed with the serial numbers of JN365830ZF, FL689155WG, LX543727CK, LX543631CK, MU919682BT and MU919652BT.

Police said watermarks on the forged notes were obscure and ambiguous, while the glittering anti-counterfeit strips were merely stickers instead of being seamlessly imprinted.