The 23-year-old constable, who had been denying an affair with his colleague, was arrested on Wednesday for abetting suicide after his DNA profile matched that of the foetus of the dead woman constable, who committed suicide in April this year.
The arrested constable was identified as Kapil Dev, attached to the St Thomas Mount armed reserve and a native of Pantruti, Cuddalore.
He has been remanded in judicial custody.
The policewoman, Sammera Banu, a native of Dindigul, was found hanging by her roommates on the evening of April 15 at their residence in Alandur when they returned from work.
The reason behind her extreme step was not immediately known.
The police decided to probe the issue when the post-mortem report indicated that the policewoman was four months pregnant.
After collecting details of her mobile phone call and SMS history, the probe team examined the role of some of her friends and colleagues.
The investigators had a strong hunch that constable Kapil Dev was involved with the woman.
Dev, however, denied having an affair with her and claimed that they were just good friends.
The investigators then collected DNA sample from Dev and sent it for testing to find out if the profile matched that of the foetus.
“The result which reached us on Tuesday said the DNA profile matched, proving that Kapil Dev was certainly the father of the child,” the police said.
Only after the woman constable’s father approached the Madurai bench of the Madras high court did the detailed probe, including the DNA testing, take place.