Army Major Nikhil Handa, who is accused of killing Shailja Dwivedi, wife of his fellow officer, exchanged over 3,300 calls and messages since January with the victim, the police said.
"Nikhil told us that he was in contact with the victim since 2015. During investigation, we found that they have been talking to each other for a long time. In fact this year since January 1, Nikhil called her 3,300 times," Deputy Commissioner of Police Vijay Kumar said.
A media report said that the major first met Shailja on Facebook after he saw her picture on a common friend's timeline in 2015.He then befriended her husband to meet her. Since then the Major became a frequent visitor to their home.
The report further said that that he tried convincing Shailja to divorce her husband and marry him.
A day before the Delhi court had sent Major Handa to four-day police custody.
The police arrested Handa on Sunday from Meerut, Uttar Pradesh for allegedly killing the wife of his fellow army officer after she refused to marry him. Major Handa was currently posted in Nagaland's Dimapur.
The deceased`s body was found with her throat slit in Delhi`s Brar Square area on Saturday.
Kumar said the police have recovered "enough elements required to file a strong chargesheet in the case."
Meanwhile, the police have also found the victim's mobile phone from a dustbin in Saket.
Major Nikhil had destroyed the phone and removed the victim's SIM card.
(With inputs from ANI)