Seven people linked to a Right-wing Hindu organisation and a Hindu girl’s father have been detained after the dismembered body of a Muslim youth was found near a railway track in Belgaum last week, police sources said.

Najeema Shaikh, mother of the murdered Arbaz Aftab Mulla, 24, said members of the little-known “Sree Ram Sena Hindustan” had earlier threatened harm if the young man did not break off his relationship with the Hindu girl.

She added that the girl and the Sena had colluded in extorting money from her son.

Sources said that on September 29, a day after Mulla’s body was found, the police had seized an abandoned ambulance, with “Sree Ram Sena Hindustan” emblazoned on its windshield, near the spot.

Officially, the police said that eight people had been detained for questioning on Sunday but did not identify them or link them to any organisation. Nor did they mention the ambulance.

Mulla was found with his head and a leg severed near a railway track at Khanapur in Belgaum district, some 500km from Bangalore, on September 28. The railway police found signs that the victim had been tortured with his hands tied, and transferred the case to Khanapur police station.

The police have not revealed what the post-mortem says about the cause of death.

Najeema, who identified her son’s body, lodged a police complaint of murder against the girl’s father and members of the Sree Ram Sena Hindustan.

A larger group named Sree Ram Sene had over a decade ago gained notoriety in coastal Karnataka through acts of moral policing, such as harassing Valentine’s Day couples and thrashing women pub-goers. Sene founder Pramod Muthalik has denied any involvement with the Sree Ram Sena Hindustan.

Najeema, a teacher at a government Urdu-medium school, told The Telegraph on Monday that she and her son had been repeatedly threatened by the girl’s father, Kumbar, and activists belonging to the group, Pundalik Maharaj and Birje. All three are named in the FIR, which doesn’t mention the first names of Kumbar and Birje.

Najeema, who lost her husband two years ago, said she had told her son to end the relationship in the face of the persistent threats.

“The girl used to be our neighbour when I first moved to Khanapur (a small town in Belgaum) after getting transferred two years ago,” she said.

When she realised the two youngsters had fallen in love, she moved to a house in nearby Belgaum town, sensing the trouble the relationship could cause. “Yet they somehow managed to stay in touch,” she said.

“Maharaj asked me to take my son to meet them in Khanapur on September 26. At the meeting, I promised that my son would stay away from the girl,” she added.

“They deleted the entire contents, including messages, from my son’s phone. Maharaj threatened us, saying he had some 40 cases against him and one more wouldn’t matter.”

She added: “At that point the girl called Maharaj and asked him to make us pay a sum as a settlement. Maharaj gave us a phone number to which we paid Rs 7,000 since that’s all we had.”

Najeema said that Mulla later told her the girl had demanded Rs 90,000. “On September 27 he sold his car for Rs 70,000. But I have no idea where that money has gone,” she said. “And yet, after all that, they cut my son into pieces.”

Najeema now lives alone. Her daughter lives in Britain.In June, Dalit youth Basavaraj Madivalappa Badiger, 19, and Muslim girl Davalbi Bandagisab Tambad, 18, were found bludgeoned to death in Bijapur, north Karnataka. They were apparently in a relationship.

The police arrested the girl’s father, brother and two brothers-in-law based on an eyewitness account from Badiger’s mother, who said her son was tied to a tree and clubbed to death.