A key figure in the Boston clergy sex-abuse scandal who claims his rape conviction was based on "junk science" lost his bid for a new trial Friday when the state's highest court validated his victim's claim of recovering repressed memories.

Paul Shanley said the judge at his 2005 trial should not have allowed prosecutors to present evidence about the theory of repressed-recovered memories to explain why the victim waited 20 years to report the abuse.

The victim, now in his 30s, claimed Shanley raped him repeatedly when he was a child attending catechism classes at a church in Newton. He said he repressed memory of the abuse for two decades until he saw media coverage of the clergy scandal in 2002.

The Supreme Judicial Court agreed with a Superior Court judge who ruled earlier that repressed memory theory, or "dissociative amnesia," is controversial, but generally accepted in the relevant scientific community. The high court said the theory is supported by "a wide collection of clinical observations and a survey of academic literature."

Shanley is serving is serving a 12- to 15-year sentence for child rape and indecent assault and battery.

His lawyer, Robert F. Shaw Jr., had argued that Shanley deserved a new trial because the jury relied on misleading, "junk science" testimony about repressed memories by prosecution witnesses.

"The scientific community overwhelmingly believes that there is no evidence of this," Shaw said Friday, after the ruling was released.

"We believe without any hesitation that these convictions are unjust, and we have done everything possible to demonstrate that," he said.

Middlesex District Attorney Gerry Leone, whose office prosecuted Shanley, did not immediately return a call seeking comment.

A victims' support group, the Survivors Network of Those Abused by Priests, praised the court's decision.

"Let's hope this ruling will encourage others who were hurt by sex offenders to come forward, get help, expose predators, protect others and start healing," SNAP President Barbara Blaine said in a statement.

During Shanley's trial, the victim tearfully described how the popular priest used to pull him out of classes and rape him, beginning when he was just 6 years old and continuing until he was 12.

Shanley, now 78, was known in the 1960s and 1970s as a "street priest" who reached out to Boston's troubled youth. Internal records showed that church officials were aware of sexual abuse complaints against him as early as 1967.

The clergy sex abuse crisis erupted in Boston in 2002 after church records were made public showing that church officials had reports of priests molesting children, but kept the complaints secret and shuffled some priests from parish to parish rather than remove them.

The crisis, which led to the resignation of Boston Cardinal Bernard Law, spread as similar sexual abuse complaints were uncovered in dioceses across the country.