Thirty-nine Indians kidnapped by the Islamic State (IS) terror group in Iraq's Mosul in 2014 are dead, External Affairs Minister Sushma Swaraj said on Tuesday.

The minister confirmed the deaths in the Rajya Sabha and said the mortal remains will be brought back to India by Union Minister of State for External Affairs V.K. Singh.

"General V.K. Singh will go to Iraq to bring back the mortal remains of the Indians killed in Iraq. The plane carrying the mortal remains will first reach Amritsar, then Patna and then go to Kolkata," Sushma Swaraj said.

She said the bodies were spotted using deep penetration radar and were exhumed from mass graves. 

Their identities were confirmed by DNA tests.

"The bodies were brought to Baghdad for DNA testing. The DNA of 38 Indians have been matched.

"For verification of the bodies, DNA samples of their relatives were sent there. Four state governments -- Punjab, Himachal Pradesh, West Bengal and Bihar -- were involved in the process," the minister said.

The victims -- 31 from Punjab, four from Himachal Pradesh and four from Bihar and West Bengal -- were construction workers and were employed by an Iraqi company in Mosul.

They were taken hostage when the IS took control of Mosul, the second largest city in Iraq. The workers were trying to leave Mosul when they were taken hostage.

Sushma Swaraj also dismissed claims of Harjeet Massi, one of them who escaped from Mosul.

"He was not willing to tell me how he escaped," she said.

The minister said that she had concrete evidence that he was lying.

Massi had escaped along with Bangladeshis with the help of a caterer with a fake name 'Ali', she said.

She said the details were revealed to her by Massi's employer and the caterer who helped him.

In July 2017, Sushma Swaraj had said that she would not declare the 39 Indians dead without concrete proof or evidence.