Image caption What Mohammad Arif Ali and his brother did shocked Pakistan

Tracking down the two brothers convicted following a notorious act of cannibalism in Pakistan is no easy task - the duo are keeping a low profile after being released from prison.

We began by following an oxcart-rutted dirt track for as far as it would go in Punjab province. Then we walk another kilometre or so through humid maize and sugarcane plantations to reach the farmhouse.

The brothers are not there, their uncle, Wali Deen, tells me. He is also not happy to see me.

"Interview the corpse-eaters? They didn't eat corpses. They are just the victims of their neighbours' jealousy," he says defiantly.

Mohammad Farman Ali and Mohammad Arif Ali were sentenced to two years in jail for stealing a corpse from a grave and using it to make meat curry.

Image caption Wali Deen insists that his nephews are not cannibals

Because they killed no one and there is no law relating to cannibalism in Pakistan, the pair only served about two years in jail for desecrating a grave following their arrest in April 2011.

The overwhelming evidence of cannibalism created a serious law and order situation in the area around the small desert town of Darya Khan, located along the western fringes of Punjab, some 200km (124 miles) south of the capital, Islamabad.

In June, people of the town were stunned when the brothers were released from jail. Angry protesters set tyres on fire on a major highway in the area, blocking traffic for several hours.

The police had to take the brothers into protective custody to prevent them from being lynched. Their whereabouts since their release have been largely unknown.

Room of horror

We decide to search another of the family's abodes - an abandoned house in a semi-urban locality near to Darya Khan town.

It still gives me the creeps; they had chopped off one of her legs below the knee, and the other one near the shin Inspector Fakhar Bhatti, Police officer

It is here we find the younger brother, Arif Ali, lying in a charpoy cot under a thatched shed in one corner of the courtyard.

Breaking into a cold sweat at being discovered, he has few answers for the atrocity he committed and appears to be more concerned for his own safety.

"It happens you know, that [people get killed]," he tries to explain in an unsteady tone, "so [I am afraid] I could get in trouble."

In fact Mr Ali, who is in his early 30s, does not have a coherent answer to a single question I put to him. I can't decide whether he is mentally unstable, or just nervous. He does express hope, though, that such a grisly incident "will not happen again".

"Everything will be alright… God willing," he says, as if to comfort himself.

But the state of the house does not suggest this hope will be fulfilled. It is strewn with dried branches and debris from crumbling walls.

One end of the courtyard comprises a storeroom and two rooms. Another room is locked and another contains only two pieces of furniture - an aging rope-woven charpoy on which some clothing is dumped, and a steel framed swinging crib for babies.

This is Arif Ali's room. He once lived here with his wife and a baby boy.

It turns out that the next room, which is locked, is where the horror unfolded two years ago.

Stale smell

It all started after a 24-year-old woman, Saira Parveen, died of throat cancer and was buried by her relatives. The next morning, some women of the family visited her grave and found that it had caved in.

Image caption The house where the cannibals ate their meal has been all but abandoned

"We opened the grave, and were horrified to discover that the body had gone. We called the local elders, who called the police," says Aijaz Hussain, the dead woman's brother.

Police investigations led them to the house of the Ali brothers.

"We raided the house in mid-morning in the presence of local elders," says Inspector Fakhar Bhatti, the police official who led the raid.

"Arif was sleeping in his room. His father and one of his sisters were there. Farman was absent. We searched the house, and then asked for the key to Farman's room, which was locked."

When they opened the room, a stale smell of cooking and dead flesh hit them.

"In the middle of the room, I saw a cooking pot which was half full of meat curry. Nearby was a wooden board, a butcher's axe and a large kitchen knife. Bits of fat clung to the board and the blade of the axe."

The food had attracted a colony of ants; their line vanished under a bed.

"We followed the ants. There were a couple of sacks of fertiliser under the bed. We pulled them out, and behind them, inside a gunny bag, we found the body," says Inspector Bhatti.

"It still gives me the creeps; they had chopped off one of her legs below the knee, and the other one near the shin. The rest of the body was intact. The curry was made from those parts. We got it analysed at a laboratory in Multan."

When questioned by the police, the brothers admitted to having dug up and devoured several other dead bodies from the local graveyard. They said they had been doing it for a couple of years.

'Sorcerer'

The question is, how did they get into such a macabre business?

Image caption Aijaz Hussain discovered that his sister had been dug up from her grave

Inspector Bhatti says the police came across leads that the Ali brothers had been in touch with a man accused of being a sorcerer who locals caught stealing a body from a grave some years earlier.

"We couldn't follow up on that lead because the man disappeared without a trace," he says.

During interrogation, Farman Ali admitted that he had written "certain verses of the Koran in reverse as a way of casting a spell on his neighbours", said Inspector Bhatti.

"He said for the spell to be effective, the brothers had to remain unclean and eat human flesh."

Farman Ali was not always like this, says Tanvir Khwawar, a local resident who studied with him in the same school for 10 years.

"He was intelligent, and studied science in the 10th grade, whereas I was just an ordinary student who went for humanities.

"But after the 10th grade, he gave up studies, and became increasingly secluded. We seldom saw each other after that."

Both brothers got married and had children. But their wives left them a couple of years prior to their arrests.

Inspector Bhatti, who traced both women and questioned them, says they complained that their husbands did not work, beat them and locked them up in the house when they went out, often at odd hours.

A sister who lived with them was mentally disabled and was found drowned in a canal a few days after their arrest.

The brothers were never examined by a psychiatrist for any personality disorder.

Defence lawyer Rao Tasadduq Hussain said his job was only to secure a minimum jail term for them, which he did successfully.

"They are not insane, they are just fools," he told me.