A nursery worker used hidden cameras to film up children's skirts and make secret recordings of women going to the toilet.

James Hoffman, of Purley, pleaded guilty to eight charges of voyeurism, and four of possession of indecent images of a child, at Croydon Crown Court on Wednesday.

The 34-year-old was caught after he was arrested on May 24 after the discovery of a recording device hidden in an adult toilet at a nursery in Sutton.

A raid of his home found recordings dating back over eight years.

The recordings included sixty minutes of footage prosecutors believe is of children aged between five and eleven at an after school club.

A camera was used to film under desks and up girls' skirts. It has not been possible to identify any of the victims in the footage.

A further 25 minutes of footage was found filmed over a fence of half-naked children playing in a garden.

The films also included at least 16 secret recordings of people going to the toilet. Two victims have been identified but a number are still not known.

At the hearing on Wednesday Hoffman remained calm as he pleaded guilty to each of the 12 charges as they were read to him.

The court heard Mr Hoffman, who worked for the Jancett Group of nurseries, may have Asperger syndrome.

The charges stated he made the films without his victims' permission for the purpose of his own sexual gratification.

Ten indecent images of children were also found on Hoffman's laptop in the police raid.

They included an image at level five, which are classified as the most extreme images of child pornography, that can include sadism.

He will be sentenced at Croydon Crown Court on September 20.

The sentencing was adjourned while a mental health report and a probation report on Hoffman are prepared.