An unaccompanied eight-year-old boy has been held at Paris’s main airport for more than a week after trying to enter France with false identity papers.

Children’s rights campaigners have accused the French authorities of breaking international child protection laws by refusing to let the youngster join relatives in France.

The boy, who has not been named, was put on a plane to Paris from the Comoros Islands in the Indian Ocean, off the coast of south-east Africa, more than a week ago by his mother who, according to French and African media, wanted him to have a better life.

Carrying just a Spiderman backpack, he was arrested on arriving at Roissy-Charles de Gaulle airport on 21 March and detained in an airport holding area for those suspected of trying to enter the country illegally, after reportedly producing a French passport in his cousin’s name.

The French appeal court decided he must be held in the waiting area for his own protection.

But Catherine Daoud, a child protection lawyer, told French radio: “The imprisoning of children in the [airport] waiting area, especially young children like this, is against the international convention on child protection signed and ratified by France.”

She added: “Sadly, his is not an unique case. It’s shocking to see a young kid stuck in the same basket as the adults and with the police … for the child it’s a prison.

“What shocks us is that he is shut in. Why is he shut in? We’re talking about a place with bars, it’s no place for a child.”

The French interior ministry said on Wednesday that the boy’s mother had asked for the child to be returned to her.

The authorities were trying to organise for someone to accompany him back to Comoros, but the process had been delayed because of the Easter holiday, a ministry spokesman told the Guardian.

“The boy arrived with a borrowed passport and was in an irregular situation in French territory,” she said.

“This was confirmed by the police and he was placed in the waiting area. The judge for liberty and detention decided it was in the boy’s best interest to keep him in the waiting zone until inquiries could be made.

“The French authorities made contact with his family and his mother said she wanted to take this young boy back.

“On 25 March, the court of appeal decided he should remain in the waiting zone until he could be returned.”

She added: “It’s not for the ministry to question legal decisions. Obviously he is being correctly treated and is with someone from the Red Cross [at the airport].

“We want this child to be returned to his country of origin as his mother has requested, but accompanied this time.”

Daoud said 259 lone minors had been kept in the holding area in 2014. Like adults arriving in France without papers, they can be held for up to 20 days before being admitted or deported.

Isabelle Thieuleux of the organisation La Voix de L’Enfant (A Child’s Voice) was at the court hearing. “We were told the French administration had to be given time to organise the boy’s return to Comoros,” Thieuleux said.

“He left the hearing accompanied by two police officers. His bag was almost bigger than him, he was just a little thing.

“There’s no justification for imprisoning an eight-year-old child who has arrived in the country, and even less for the motive of his own protection. Where’s the protection for a child in such a place?”