A 29-year-old mother, who was discovered to have been spending much of her time chatting online, has been arrested in connection with the death of her 1-year-old son, police here said.

Yumiko Takahashi stands accused of parental neglect of her son Neo, aged 1 year and 7 months, who died of pneumonia on June 26, 2011. Police said that in addition to failing to seek medical treatment for her ill son, Takahashi did not change the child's diapers and left him unattended on a bed in their apartment in Otsu, Shiga Prefecture, until the disease finally claimed his life.

According to police, an employee from the nursery school Neo was attending came to pick him up at the family's apartment on the morning of June 24 and noticed that the child had a high fever. The employee urged Takahashi to take her son to a hospital, but when the person returned again in the evening to check on the child's condition, Takahashi said the fever had abated.

Three days later, at around 11:10 a.m. on June 27, Takahashi found her son's body cold and called the nursery, saying, "Something really serious is happening." When the childcare worker visited the apartment, Neo was already dead.

Based on autopsy results, however, it was estimated that Neo had died a day earlier, at around 2 p.m. on June 26. Police believe that Takahashi, who was reportedly spending a considerable amount of time in online chat rooms, may have been chatting and doing other things even after Neo's death.