Police said Thursday they have arrested the developer of a "spyware" program that was used in the theft of 216,000 yen from a Japan Net Bank account last year.

Atsushi Takekawa, 31, a former employee of an information technology company, admitted to having developed the program, which is designed to steal data from computers, police said.

It was the first arrest in Japan of a spyware developer, they said.

Takekawa is suspected of conspiracy with Kiichi Hirayama, 41, attaching the spyware to an e-mail message sent to a jewelry company in Kawasaki in June to steal its online ID and personal identification number, police said. In the e-mail, they pretended to be customers complaining about merchandise bought at the company.

Takekawa and Hirayama then used the information to transfer about 216,000 yen from the firm's account at the bank to Hirayama's account the following month.

Hirayama has already been charged in the theft.

Takekawa was quoted as saying Hirayama asked him to develop a spyware program, police said.

They also alleged the two men were involved in other cases in which they are suspected of stealing a total of 11 million yen online from the bank accounts of 10 mail-order retailers.

Hirayama indicated earlier that he tried to swindle money out of corporate depositors of banks by sending them CD-ROMs that, when run on a computer, would install the spyware, police said.

They said they suspect Takekawa was also involved in these cases.

Spyware secretly gathers information from a computer and can transmit it over the Internet to an intended recipient.