The MP for East Belfast was speaking on Friday after the latest information came to light.
Naomi Long MP said: “The allegations by a former army intelligence officer regarding his investigations of Kincora simply reinforce that allegations of abuse at the home should be included in the Home Secretary’s UK-wide inquiry.
“To be told to cease any investigation into child abuse, no matter what source allegedly told him to do so, is deplorable and adds to the sinister nature of claims about the home.
“We owe it to the victims to expose any wrongdoing that took place at Kincora, both to deliver them justice and ensure nothing like this happens again.”