BOSTON (Reuters) - One of the world’s most notorious hackers claims he may have a form of autism and has asked a judge to be lenient in sentencing him for helping mastermind the biggest identity theft in U.S. history.

The judge has delayed sentencing Albert Gonzalez in Boston federal district court for three months, to give prosecutors time to assess the hacker’s claim that he may suffer from Asperger syndrome.

Gonzalez’s attorney hired a psychiatrist who determined that the hacker’s criminal behavior “was consistent with description of the Asperger’s disorder” and “Internet addiction,” according to court documents.

Asperger syndrome is a mild form of autism. Sufferers’ interests in specific subjects may border on the obsessive, according to the Autism Society.

Prosecutors assert that Gonzalez led a group of hackers who broke into computer systems and stole more than 170 million payment card numbers from data processor Heartland Payment Systems as well as retailers TJX Cos Inc BJ’s Wholesale Club Inc and Barnes & Noble.

Gonzalez, a former government informant, has plead guilty to the charges. Yet he contends he was not the mastermind behind the attacks.

He faces a prison sentence of 15 to 25 years, and has forfeited $1.1 million in cash, a Miami condominium, a Glock pistol and several computers, according to court documents.

Gonzalez’ attorney, Martin Weinberg, said in a court filing that he sought a minimum sentence because a psychiatrist had found that his client suffered from “diminished capacity.”

The court has sealed the details of Weinberg’s request.

Prosecutors said that the psychiatrist questioned the hacker’s “capacity to knowingly evaluate the wrongfulness of his actions and consciously behave lawfully and avoid crime.”

(Reporting by Jim Finkle)