Police in Kobe have arrested a 26-year-old man on suspicion of trespassing and theft after he broke into a female acquaintance's house with a stolen key. 

According to police, Kaito Hamanaka, a Kobe Detention House guard, has partially denied the allegation and quoted him as saying "I didn't steal the key. It was left in my mailbox."

Hamanaka is accused of breaking into the house of the woman, who is in her 20s, between Sept 1 and October 18, stealing a key, and then using that key to again enter the house at around 10:35 a.m. on Monday, Sankei Shimbun reported.

After noticing something suspicious, such as objects being moved around inside the house, the woman responded by installing a security camera. Footage showed Hamanaka in her house on Monday.

Hamanaka turned himself in at a police station on Wednesday.