OSAKA--The adopted son of a woman found dead at her home in Takatsuki, Osaka Prefecture, was arrested for the third time on Aug. 25 on suspicion of murdering her, investigative sources said.

He is suspected of killing her and making claims on her life insurance policies after her death.

Naoko Takai, 54, was found dead in a bathtub at her home.

Rin Takai, 28, who resides in Kawasaki, Kanagawa Prefecture, with no occupation, was arrested in July on suspicion he forged a private document with a signature or seal, then used that document when he forged and used a form to register for adoption.

He was arrested again on Aug. 10 on suspicion of fraudulently avoiding making a payment when he purchased a bag and other items at a large retail store in Tokyo on the morning of July 22 last year.

Life insurance policies worth about 150 million yen ($1.1 million) had been taken out on Naoko.

She worked for a group company of a city bank.

Rin is suspected of drowning her in a bathtub filled with water at her home in Takatsuki on July 22 last year, according to investigative sources.

Naoko was unmarried and lived on her own.

Rin is also suspected of changing the beneficiary of life insurance policies she had from Naoko's mother to himself using a forged document concerning the insurance contracts in or around May of last year.

Investigators believe he filed a claim on the policies after her death.

Though he didn’t receive the insurance benefits, he inherited Naoko’s savings and other money worth around 100 million yen.

He approached Naoko and sold two life insurance policies from different insurance companies to her, worth around 100 million yen and about 50 million yen, respectively, when he was selling insurance for the period from 2018 to 2020, according to Rin’s former employer and other sources.

According to prefectural police, Rin became Naokos adopted son in February last year by submitting an adoption registration form at Takatsuki city hall, after which his surname changed from Matsuda to Takai.

Police believe Rin sought to receive the insurance benefits as her beneficiary after becoming her adopted son.

Before he was arrested, Rin denied any involvement in Naoko’s death at a voluntary police interview.

“I was in Tokyo and didn’t go to Osaka,” he said, according to investigative sources.