A Nigerian man has been rescued from the garage of his parents' house in the northern city of Kano, where he had been locked up for three years, police say.

Ahmed Aminu, 30, was discovered after a police raid on the family's residence.

Neighbours had alerted a local NGO about his plight, and the police were then called.

Mr Aminu's father and step-mother have been arrested and police say further investigations are under way.

In a horrific video shared on social media, an emaciated Mr Aminu, too frail to walk, was assisted into a vehicle as he was taken to hospital.

He had visible calluses on his knees and his bones were apparent through the little flesh left on him.

"We found Aminu in a terrible situation, urinating and excreting in same spot without [being] given any food and looking like he was going to die at any moment," Haruna Ayagi, head of the Human Rights Network NGO, told the BBC.

Police said the man had been locked up by his parents on suspicion of drug abuse and left without proper food and health care.

Some reports said he had been locked up for seven years.

This is the second time this week a victim has been rescued from horrific conditions in their parents' house in Nigeria.

On Wednesday, police in north-western Kebbi state rescued a 10-year-old boy from an animal pen where he had been kept for two years by his parents.

The BBC's Nduka Orjinmo in Abuja says that northern Nigeria has a drug addiction problem but with few state-funded facilities, some parents are resorting to self-help for their troublesome children.

Some parents have sent their children with drug problems to private religious rehabilitation centres, but some of those have been raided by officials who described them as "torture houses".

A BBC investigation in 2018 exposed horrifying conditions at a state centre in Kano, where patients with mental health issues were chained to the ground.