The 39 Indian workers who were killed in Iraq’s Mosul after being kidnapped by the Islamic State in 2014 were shot dead more than a year ago, the Hindustan Times reported on Thursday.

Most of the workers were shot in the head, forensic tests results showed, according to the report. The newspaper quoted the head of Department of Forensic Medicine Dr Zaid Ali Abbas as saying that “most of the bodies had gunshot wounds on the head”.

“When the remains came to us, they were just skeletons, only bones,” Abbas said. “They had no muscle or tissue. Forensically, I can confirm that they definitely died over a year ago.”

In June 2014, Islamic State militants reportedly abducted 40 Indian labourers from a construction site near Mosul. Most of the victims were from low-income families in Punjab.

On Tuesday, External Affairs Minister Sushma Swaraj informed Parliament of the death of the 39 workers. She said the government has confirmed that all the Indians were dead, after their bodies were exhumed and a DNA analysis was done.

The news invited criticism not only from Opposition parties, which asked why the government had kept the families’ hopes alive for almost four years, but also the families of the workers, who asked why they were not told about the deaths before Parliament was informed.

Harjit Masih, one of the Indian workers who managed to escape and return to India had earlier described how the Indian hostages had been lined up and shot. However, at a press conference earlier this week, Swaraj said that his version of events did not check out. Swaraj maintained that the cause of the deaths would become clearer once forensic certificates are released to India.

Dr Abbas told the newspaper that the remains will be handed over to the Indian embassy in Baghdad soon.