A mother-and-son pair in the Kansai region arrested on suspicion of obstructing business at hotels allegedly cost accommodation facilities ¥115 million in damages after they made around 3,200 booking cancellations in one year, investigative sources said Wednesday.

Yukiko Kishida, 51, and her son Yukihiro, 31, were arrested last month for allegedly repeatedly ditching reservations made through the Japanese online booking site Ikyu.com at four accommodations in Kyoto last August. The pair is suspected of acquiring a large amount of rewards points and using them to stay at different hotels.

On Wednesday, they were served a fresh arrest warrant over similar charges for not showing up for around ¥94,000 worth of bookings at three properties in Shiga, Kyoto and Nara prefectures last November.

Using fake names and contact details, Kishida and her son created a large number of accounts for use on Ikyu.com and booked stays across the country.

Customers usually acquire 1 percent of their accommodation fees in rewards points, but can get up to 20 percent back in points for same-day bookings. The pair is suspected of making false same-day reservations to acquire the rewards points.

In some cases when a hotel forgets to notify the booking site of a cancellation, customers still receive points even if they don't show up.

The pair allegedly stayed in hotels using around ¥2.5 million worth of T-Points that they had obtained illegally, the sources said.

Ikyu Corp., the operator of the booking site, is a subsidiary of Z Holdings Corp., which runs Yahoo Japan's online services and is a unit of SoftBank Group Corp.