Calcutta, April 10: Piyali Mukherjee, the young lawyer found hanging in an upscale New Town apartment on March 26, made the last call before her death to a number used by state transport minister Madan Mitra, The Telegraph has learnt from police sources.

Call details of Piyali’s number available with the police reveal that between March 17 and 26, the last 10 days of her life, the two spoke on 75 occasions for a total of almost five hours. (See chart)

Her last call, made at 10.05am from a Reliance number registered in the name of Piyali Chakraborty (her husband’s surname), went to a Vodafone number Mitra has been using for several years.

When The Telegraph called the Vodafone number, Mitra, admitted to a private hospital, picked up the phone. He said: “I cannot comment as an inquiry is in progress.”

Asked if he spoke to Piyali at 10.05am on the day of her death, Mitra replied: “I didn’t take the call.”

“No, no… I woke up at 11-11.30am… I usually get up around 11.30-12noon. There are people to attend my calls,” added Mitra, who is holding the twin charges of the transport and sports ministries.

Piyali, 28, was found hanging when the police broke the lock to the flat on the ninth floor of Siddha Pines. As there was no complaint from anyone in the family, the Bidhannagar commissionerate started a case of unnatural death.

Although call records show she spoke to someone using phones associated with Mitra twice that day, the police are yet to question the minister.

As Piyali, a Trinamul Chhatra Parishad leader from Burdwan, had been seen with Mitra in several public places, the minister had faced questions immediately after her death. Mitra’s reply was that he had known her and her family through the party.

Married to a teacher and the mother of a six-year-old daughter, Piyali used to live alone in a rented flat at Siddha Pines near the airport as she pursued a career as a lawyer in Bankshal Court.

Her last call lasted 34 seconds. A little over 20 minutes before that, at 9.42am, Piyali’s call records show a 10-minute conversation when a call came from a number associated with the minister. Of the 75 occasions contact was established between Piyali and four numbers used by Mitra during the last 10 days of her life, Piyali was the caller 41 times. The remaining 34 calls she had received from these four numbers.

Asked if he did not speak with Piyali on all these 75 occasions, Mitra said: “Na na… kono shomoy hoyto kotha hoyechhe… kintu police inquiry cholchhe… police jodi jiggesh kore… police ke janabo (No, no… maybe sometimes I did speak to her… but now a police inquiry is going on… if the police ask me… I will tell them).”

Calls went back and forth between Piyali’s number and the four numbers Mitra uses, three of which are registered in his name at his 32B DN Ghosh Road, 700025, address. The fourth, on which The Telegraph called him and he answered, is in the name of Swarup Mitra of 36/1, Chandranath Chatterjee Street.

These numbers, in The Telegraph’s possession, are not being revealed to protect Mitra’s privacy.

Mitra confirmed that two of the three numbers that this newspaper mentioned as a part of Piyali’s call details, are his “private numbers”. The third number, too, is registered in his name with BSNL, this newspaper has found. Mitra, however, said that often others take or make the calls on his behalf.

He said: “I have eight to 10 numbers. Whenever I need, I ask people to make the calls.”

He added: “It’s a common allegation against me… that I don’t receive calls or I don't call people… I have so many phones… so many people call me…. It is not possible for me to reply to your question like this.”

This raises the possibility that though Piyali’s call records reveal calls to and from numbers associated with Mitra, she could have been speaking not to the minister but someone — one person or more — who was using his number. And not just one number, but all four. The call details do not throw any light on the cause of her death either.

There was also a series of calls from Piyali to a number registered in the name of Shekhar Agarwal (of Sri Ram Krishna Apartment, 89/63, Bangur Park, 3rd lane, 4th Star, Rishra, Hooghly — 712248) in the hours leading up to her death. She dialled the Agarwal number after receiving a call from one of Mitra's phones shortly before the midnight of March 25-26.

When The Telegraph called the number Piyali had rung 24 times in the 10 days before her death, a man answered but did not identify himself: “There is no Shekhar Agarwal here.”

Asked about the calls from and to Piyali’s number, he said: “I will have to check who made the calls.”

Soon after receiving the call from the minister’s number before midnight, Piyali called the Rishra number three times, the last at 12.38am. Again, on the morning of her death, between the two calls exchanged with the numbers belonging to Mitra, she phoned Agarwal twice.

“Even if it is a case of suicide, the pattern in which she allegedly made the calls in the last few minutes of her life suggests she decided to end her life on the spur of the moment,” said a criminologist.

Twenty-four hours before her death, she had called a woman to ask when the cosmetics she had ordered earlier would be delivered, people who had spoken to Piyali over the phone told The Telegraph.