The police watchdog has launched an investigation into a complaint about the treatment of a disabled 11-year-old girl who was restrained by officers.
The girl, who has Smith-Magenis syndrome, a genetic disability, appeared to be physically restrained with handcuffs and leg restraints by officers on five occasions in and around Horsham, West Sussex.
On four of the occasions that she came into contact with Sussex police officers she was arrested and taken to police stations, and she was held overnight twice.
The girl's mother complained to the Independent Police Complaints Commission (IPCC) about the way police managed the incidents between 2 February and 2 March last year. She also complained about the methods of restraint used on her daughter, and the decisions to hold her in police station cells overnight.
The IPCC commissioner, Mike Franklin, said: "The IPCC investigation is examining the nature and circumstances of the officers' interaction with the girl on five separate occasions in February and March 2012 to determine whether the degree of force and method of restraint used by officers was appropriate and in accordance with the law, the officers' training and force policy and procedure.
"The investigation is also looking at the appropriateness of the decision to place the girl in police cells on four occasions and to refer her to the Crown Prosecution Service for charging on one occasion.
"These are very serious complaints about the treatment of an 11-year-old girl suffering from Smith-Magenis syndrome and I will ensure that they are investigated thoroughly."
A Sussex police spokesman said: "We take our responsibility for any use of force very seriously, particularly when it involves young people or those who are disabled.
"Given the unusual circumstances of the case and that it is being independently investigated, we cannot go into full detail until the conclusion of the investigation. We welcome the IPCC's scrutiny and we fully support its investigation."
According to the Smith-Magenis Syndrome Foundation UK, its major features include mild to moderate intellectual disability, delayed speech and language skills, distinctive facial features, sleep disturbances, and behavioural problems.