A family of five who were hanged in a bizarre murder-suicide ritual were left to swing from their ropes until their bodies rotted, say police investigating the case.

Officers in Najafabad, Isfahan, discovered the gruesome deaths when they broke into the family home after a relative raised the alarm.

Inside they found four mummified bodies still hanging from their ropes.

A fifth was discovered on the floor because it has decomposed so badly it had dropped through its noose.

Suicide notes were found for four of the dead but police believe the fifth victim – named as teenage girl Negar Haji Reza Talebi – had been murdered.

Like a scene from a horror movie, a woman, her son and two daughters had strung themselves up on a metal bar and locked the doors.

The youngest victim had either been tricked or forced into a noose too, police believe.

Gas and electricity at the property had been cut off and the family car was parked in the drive.

One neighbour told local media: “One of the bodies of the victims was lying on the ground, which was probably separated from the rope after the passage of time.

“All the bodies were dried, which indicated that a lot of time had passed since the fatal incident.”

All of the women had their hands tied behind their backs before they had been hanged by the son, police believe.

He had then climbed onto a chair and put his own neck through a noose before kicking it away and dying as well.

Police named the four suicide victims as widow Fatemeh Aini and her children Maryam Sadat, Elham Sadat, and Seyed Ali Akbar.

One neighbour said the family explained that Aini had been depressed since the death of her husband Seyed Hossein Al-Madizi.

Abolfazl AbuTorabi, a member of Najafabad’s parliament, confirmed that the police investigation had found that the son and mother had been depressed for years and that the son had carried out the family’s plan to kill themselves which included tricking the teenager.

He confirmed: “Handwritten notes made it clear that suicide was the reason for the death of most of the family members, and that depression and isolation was the motive for their actions rather than economic problems.”