A convicted sex offender has been jailed for taking part in a sex act in front of a young girl.

Richard Ling also failed to tell police he had changed his address under a sex offences prevention order.

Ling, 54, claimed the incident involving the little girl never took place but he was convicted by a Chelmsford Crown Court jury after a trial last year.

Sentence had been adjourned for reports but the case was delayed when Ling was accused of breaking a condition of a sex offences order by loitering near a Clacton school.

He denied this charge and the prosecution offered no evidence against him when he appeared in court.

Stephanie Farimond, prosecuting, said it could not be proved Ling had loitered at the Coppins Green School in Clacton on November 27 as he had only been seen in the area for four minutes.

Ling was jailed for 18 months on the sexual activity charge.

There was no separate sentence for the address charge as Judge Peter Fenn said it had been a "technical" breach.

Last year's trial heard Ling was seen in the garden of an empty house in Salerno Crescent, Colchester, on July 25 2006.

The house was near to a children's play area and a nine-year-old girl and a friend were sitting on a wall when Ling was seen by a neighbour carrying out an indecent act.

He was arrested a few days later after another neighbour saw him in the area and told police.

Ling, from Wellesley Road, Clacton, had denied a charge of engaging in sexual activity in the presence of a child for the purpose of obtaining sexual gratification.

He admitted being in the area at the time but denied being in the garden of the house and said nothing indecent had taken place.

The court also heard Ling admitted failing to tell police of a change of address from North Road, Clacton, to his present address after an earlier court hearing.

Nneke Adudolu mitigating, said Ling accepted the jury had convicted him on the sexual activity matter but he still denied the charge.