A British teenager accused of attacking websites as part of an international hacking group has been remanded in custody, despite being diagnosed with autism.

Ryan Cleary, 19, appeared at a London court on Saturday charged with offences including hacking into the website of the Serious Organised Crime Agency (SOCA), the British equivalent of the FBI.

Judge Nicholas Evans initially granted him bail after his defence team said the teenager had been diagnosed with Asperger's syndrome, a form of autism, since his arrest.

However the decision was swiftly overturned after objections by prosecutors. His bail appeal will be heard on Monday.

Police arrested Cleary on Monday last week at his home in Wickford, southeast England, as part of a probe by Scotland Yard and the FBI into the Lulz Security hacking group.

Lulz has claimed responsibility for a month-long rampage against international businesses and government agencies, including the CIA and Senate in the United States and electronics giant Sony.

Cleary was in court for the second time in three days. He did not enter any plea to the five offences under the Criminal Law and Computer Misuse Act with which he is charged,

Ben Cooper, defending Cleary, expressed concern about his client's welfare given the recent diagnosis of Asperger's. He told the court Cleary is extremely intelligent but agoraphobic and has difficulty interacting with other people.

British police on Wednesday charged Cleary with targeting the website of SOCA with a Distributed Denial of Service (DDoS) attack.

DDoS attacks overwhelm websites with requests, causing them to be slow or inaccessible.

He was charged with similar attacks on the website of the International Federation of the Phonographic Industry (IFPI) in November and the British Phonographic Industry (BPI) on October.

Cleary faces two further charges of creating a "botnet" or network of computers to carry out DDoS attacks. Lulz has denied that Cleary was part of the group.

His case closely mirrors that of Gary McKinnon, a Briton who also has Asperger's and is fighting extradition to the United States over allegations of hacking into US military computers

- AFP