THE family of a 15-year-old east Hull boy locked up overnight by police in a case of mistaken identity are claiming he was arrested and detained unlawfully.

Joshua Stevens was arrested at his family home on Kyffin Avenue in January, accused of sexually assaulting a 14-year-old girl. He spent 13 hours under lock and key.

Joshua was fingerprinted, had his mug shot taken and a saliva swab used to get a DNA profile – despite it eventually surfacing that his arrest was a case of mistaken identity.

Now, acting on behalf of Joshua, Williamsons Solicitors have alleged that the arrest was wrongful and that he was detained unlawfully.

They claim he should not have been arrested, the decision to detain him was not considered properly, and officers failed to act on information about the identity of the true offender – both before Joshua arrived at Priory Road police station and on several occasions throughout the time he was locked up.

They claim that if that in itself is not considered unlawful, then it became an unlawful detention once police were aware they had the wrong boy.

Alan Stevens, Joshua's father, said he hoped the legal claim would reveal the full facts which led to his son's arrest.

"All I want to know is how my son found himself in a situation where he spent a night in the cells having done absolutely nothing wrong," he said.

It is also claimed the Police and Criminal Evidence Act 1984 was breached on numerous occasions.

The family's letter of claim states that several officers failed to act on information received to identify the correct offender.

The letter, which has been sent to Humberside Police's chief constable, Tim Hollis, says that Joshua was falsely imprisoned for seven hours as his detention was not reviewed after six hours – an alleged breach of the Act.

Joshua's jumper was also taken from him without a valid reason, leaving him cold and uncomfortable in a dirty cell.

The solicitor's letter claims Joshua's parents were not informed of his arrest and that his medical condition, asthma, was not properly considered, leaving him without his inhalers for the duration of his detention.

Mr Stevens said: "Joshua still struggles trying to come to terms with what happened to him.

"I am traumatised for him, so I have no idea what he must be going through."

The letter states: "In consequence of the above, our client was deprived of his liberty ... he suffered distress, anxiety, inconvenience, loss of amenity and his condition of asthma was exacerbated. Joshua's parents lost the cost of their holiday weekend."

"Our client claims damages for his losses and his father seeks to recover the cost of the holiday he and his wife lost."

The family is yet to receive a response from the force, but have asked for disclosure of all the logs, evidence, intelligence and police notebooks in relation to the incident.

Despite the ongoing claim, the Stevens family are claiming a victory after receiving a written apology from the force and they have been given back Joshua's DNA samples – an unprecedented move by Humberside Police.

Chief Inspector Kai Adegbembo wrote: "I personally apologise on behalf of Humberside Police for the negative impact that has resulted from the arrest."

A spokeswoman for Humberside Police said: "We have been in contact with Mr Stevens and we have apologised to him and to his son.

"We have received a letter from their solicitors informing us of the action they are taking and because the matter is now subject to legal proceedings it is difficult to make any further comment at this time."