An anonymous letter claiming a child was being improperly treated was sent to the authorities decades before sexual abuse allegations were formally made to the police.
Social services investigated the claims against Michael Craig at the time, but found no evidence to take the matter any further.
The alleged victim, told a jury at Teesside Crown Court Craig had abused her decades ago when she was a child, and when both of them lived in Hartlepool.
The abuse is alleged to have taken place in several locations, including in Craig's car when both of them were returning from a day out to a tourist attraction.
At about the same time, the authorities received an anonymous handwritten letter.
The court was told the letter was shown to both Craig and the girl's mother, but neither could recognise the handwriting.
Case notes made by social workers at the time said the alleged victim appeared to be a healthy and happy child, who was from a good home.
A case review a year or so later concluded visiting Craig for a second time about the matter would be a breach of his civil liberties.
In the absence of any other evidence, the file was closed.
The jury heard the alleged victim told several people of the abuse in the succeeding years, including friends, relations, and healthcare professionals.
An older relation told the court said she visited the alleged victim and found her in a distressed state.
"She was sobbing uncontrollably," said the relation.
"She was having difficulty breathing and getting words out.
"I tried to calm her, and let her go at her own pace to tell me what was wrong."
The relation added: "She said it was her fault and she was dirty.
"I told her it was not her fault, she was only a child at the time, and what happened should not have happened.
"I didn't try to question her about it, I just hugged her and comforted her as best I could."
Under cross-examination from David Potter, defending, the relation said: "My reaction to what I was told was shock, horror, and disbelief.
"I felt sick to my stomach."
Craig, 59, now of Watermill, Knaresborough, denies nine charges of indecent assault.
The case continues.