Police sources said that the arrested nurse admitted to beating the old woman. (Representational)

A nurse was arrested on Friday for allegedly torturing an ailing old woman whom she was attending for the last four months in southern Kolkata's Gangulybagan area, police said.

Sanjukta Paik was arrested by Patuli police station officers after the family members of 85-year-old Sukumari Saha lodged a police complaint and submitted CCTV footage purportedly showing the nurse beating the ailing lady, they said.

The family members had installed a CCTV camera in the room of the old lady after noticing black injury marks on her face and body.

The octogenarian's son Uttam Saha told PTI, "We had taken her to a doctor thinking that the marks could be because of some illness. But despite giving her medicines, those marks remained. We then found that it was the nurse who was beating her brutally every day. We have submitted CCTV footage to the police along with our complaint."

The old woman, who met with a brain stroke a couple of years back, was unable to move on her own and needed help even to take medicine, and hence nurses were employed by her son.

Police sources said that the arrested nurse admitted to beating the old woman.

Uttam Saha said, "She (the nurse) had become almost like our family member. I'm quite shocked to see what she had been doing to my mother. This is a criminal act.. she must be punished."