Senior security officials from MI5 and MI6 have said they have no evidence that intelligence officers were involved in, covered up or condoned abuse at the former boys' home Kincora.
The Historical Institutional Abuse Inquiry was given detailed statements from the intelligence agencies for the first time on Wednesday.
The Ministry of Defence rejected any allegation that its staff had withheld information about illegal activities at the east Belfast home.
It has long been alleged that a high-ranking paedophile ring preyed on vulnerable teenage boys at Kincora during the 1970s.
A statement from a senior MI6 manager, known only as Officer A, said a review of documents had found nothing to substantiate claims of state-sponsored child prostitution and blackmail.
He said: "I have seen nothing to indicate any involvement on the part of Secret Intelligence Service (SIS) officers in abuse at the Kincora Boys' Home or in any attempts to cover it up.
"SIS does not exploit children or vulnerable adults for operational purposes nor tolerate their abuse by the staff or those that work in their behalf or in their support, including SIS agents."