A man has been jailed for seven years after he admitted carrying out a horrific sex attack on a seven-year-old girl.

The judge today described the assault as "every parent's nightmare".

Stephen Potter, a builder and father-of-two from Olive Road, Portslade, gatecrashed a family birthday party and lured the little girl away, telling her he knew a good hiding place for hide-and-seek.

The 36-year-old divorc carried the terrified child through undergrowth, pushed her on to the ground and sexually assaulted her.

Potter admitted the offences after DNA taken from the girl's underwear was found to match his own.

He had pleaded guilty to charges of kidnap and indecent assault at an earlier hearing.

He carried out the attack just four weeks after being cleared of two rape charges and the kidnap of a 16-year-old girl.

Philip Katz, prosecuting, said the girl had been at the party in Portslade to celebrate a family member's birthday.

Lewes Crown Court heard how a man, later found to be Potter, arrived at 11.30pm and was seen loitering in the hallway. Guests thought he was a taxi driver.

Mr Katz said: "What happened thereafter can only be described as every parent's worst nightmare.

"At around midnight the parents began to round up their children and realised they couldn't find that little girl.

"They began to search and became increasing anxious when they realised she wasn't there.

"Her father searched outside and as he returned he saw his daughter in the hallway. She was crying in distress and fear. Her clothing was soaked through, there was mud on her legs, bits of twig in her hair and scratches on her legs, arms and feet."

Mr Katz said the little girl had no recollection of the attack.

Jeremy Gold, defending, said Potter had been drinking with friends before making his way into Brighton on the night of the attack.

He said he walked past the party and entered, thinking he might be able to get a drink, then saw the children playing.

Mr Gold said: "What followed was a complete aberration. He told the little girl he would help her to hide. She said her mother didn't like her going with strangers and he said, 'I'm not a stranger, I'm John'.

"Once the assault had taken place he realised the enormity of what he had done. He let the little girl go back to the party and left the scene, disgusted with himself."

Judge Richard Brown, passing sentence, said: "You subjected this little girl to a very serious assault during which you gratified your perverted desires. This is any and every parent's nightmare.

"This court has a duty to let it be known to those who indulge in such sexual behaviour that they will receive very little mercy."

Potter was sentenced to a total of seven years in prison for kidnap and indecent assault.

He must serve at least two-thirds of the sentence and on release will have his name put on the sex offenders register.