A former employee of SoftBank Corp. was arrested Tuesday for illegally taking information from the major Japanese wireless carrier on its ultrafast 5G technology before moving to a smaller rival company, police said.

The arrest of Kuniaki Aiba, who currently works for budget wireless operator Rakuten Mobile Inc., comes amid intensifying competition among mobile companies in Japan due partly to the government's pressure to cut subscription fees.

Aiba, 45, is suspected of having transferred trade secrets from SoftBank by emailing information on the company's 5G technology to his own account on Dec. 31, 2019, when he was still working for the company, in violation of Japan's unfair competition prevention law, according to Tokyo police.

Soon after, he left SoftBank and joined Rakuten Mobile, according to investigative sources.

The police did not reveal whether or not Aiba has admitted to the allegations.

SoftBank said in a statement the former employee had been engaged in building networks and took information on 4G and 5G base stations as well as SoftBanks's communication networks.

SoftBank suspects Rakuten Mobile have already used the information, which might be preserved in Aiba's business computer at Rakuten, and plans to file a lawsuit demanding its rival stop using the information and destroy it.

While Japan's three major mobile carriers -- SoftBank, NTT Docomo Inc. and KDDI Corp. -- launched 5G services in March last year, the mobile business unit of e-commerce giant Rakuten Inc. started offering them in September.

==Kyodo

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