"The case was not taken to the Crown Prosecution Service and did not reach court.
"The diary was destroyed but the relevant entry was photocopied and this formulated part of the evidence used as part of this prosecution."
Smith, 35, who denied raping the girl was convicted of three counts of rape, two of indecent assault and four counts of indecency with a child and jailed for 15 years. The tattoo artist was also placed on the sex offenders register. The case has only been made public now that the trial with the second victim has ended, he was cleared in that case.
"I am pleased that he is finally behind bars where he belongs, thanks to the current investigation team, but disappointed that it has taken nearly six years," a relative of the victim, speaking on behalf of the family, said, reported The Mirror.
She said the girl thought what happened to her at the time was normal which is why she didn't say anything. The relative also said the girl, now in her 20s, had been left feeling "numb" and that her childhood was stolen.
"Every parent wants to protect their children and she [the mother] finds it really difficult knowing she hadn't realised what was happening."
"Her daughter is strong and building a life for herself but struggles to feel things. It's almost like she has a sense of numbness.
"As a family we just want any other children who may have suffered at Smith's hands to come forward."
Detective Inspector Gary Askew said the victim showed a lot of strength throughout a lengthy police investigation and trial.
"Smith refused to accept responsibility for his crimes and this woman had to relive her abuse before a jury, who convicted Smith of multiple horrific offences," Detective Askew said.
"I hope this case illustrates that we will pursue offenders of this vile crime no matter when it happened.
"Please, if you or someone else you know is suffering as a result of child abuse, come forward and talk to someone."