Police arrested more than 10 people Wednesday, including mobsters, former loan sharks and youths, on suspicion of perpetrating a series of remittance frauds nationwide.

According to police in Tokyo, Yamaguchi and Oita prefectures, the fraud ring may have been involved in bilking people nationwide out of a combined 10 billion yen. If so, it would be the largest remittance fraud bust ever.

In remittance frauds, people are called and fed bogus stories -- including that a relative is in trouble -- to get them to send large sums of money. The scams are becoming increasingly varied and complex.

Investigators said the youths were tasked with making the phone calls. They were split up into groups, with each being ordered to amass 10 million yen a month.

The fraud ring is actually set up in the form of a pyramid, and police said they suspect that at least 70 groups with about six members each are involved.

According to an investigation, the suspects allegedly called 10 people in Okinawa, Ibaraki and Saitama prefectures last year pretending to be family members or loan guarantors. Their victims were conned into remitting amounts ranging from 1 million yen to 6 million yen each.

Police suspect the money was channeled to the underworld, investigative sources said.

According to National Police Agency statistics, some 25 billion yen was taken through such frauds from last January to November.