Police in Yokohama have arrested a 30-year-old woman in connection with the robbery and murder of a 75-year-old man at his house in Yokohama in October.

Police said Miho Kimoto, a resident of Adachi Ward, Tokyo, is the fourth person to be detained for the crime, Sankei Shimbun reported. Three men have already been arrested, police said.

Police said Kimoto, who was arrested on Saturday, and the other suspects were recruited to commit the crime on a mobile app. According to police, Kimoto says that she was instructed by an unknown man to "collect the cash," but denies being in the house and having anything to do with the robbery or murder.

The victim, Hiroharu Goto, had bruises all over his body and his hands and feet were tied. His body was found after a neighbor called 110 at around 9:30 a.m. on Oct 15 and said the window next to the front door had been broken.

Police said the front door was unlocked and the bay window was broken large enough for a person to pass through.

There were also multiple footprints found inside the house, and some of the dressers and other items showed signs of having been opened and ransacked, police said.

About 200,000 yen was stolen from the house.

Kimoto emerged as a suspect after security camera footage near a park in Tokyo showed one of the other suspects handing the cash to Kimoto.

Police have not released any information on what Kimoto did with the cash.

Police are investigating a wave of crimes being committed by people recruited via mobile phone apps.