Police in Tasmania have confirmed no further charges will be laid in the case of a 12-year-old girl who was sold for sex, based on the advice of the state's top prosecutor.

Investigators also say they have never located a list of the girl's clients.

Police have released a statement saying they had investigated phone records in efforts to prosecute more than 100 men who paid to have sex with the girl.

The 12-year-old was sold for sex by a pimp, Gary Devine, and the girl's mother last year.

Both are serving 10 years in jail for the crime.

The ABC has reported that the records showed the mobile number of one police officer was used to respond to a newspaper advertisement placed by Devine.

Police now say the numbers of three police officers have been linked to the case, but none of the officers were clients of the girl.

In one case, they say an officer's phone was used by someone else who is not a police officer.

They also reject reports that a diary or list exists naming the girl's clients or that some of the men were offered immunity in return for evidence.

Worrying message

Tasmania's Commissioner for Children says the decision not to lay any more charges sends a worrying message.

Paul Mason says the decision needs an explanation.

"[They need] to satisfy the public that none of the people who were suspects in this case are in positions of responsibility or influence over children," he said.

Mr Mason says he is disappointed the Attorney-General Lara Giddings has decided not to exercise her perogative to review the evidence.

Steve Fisher from the group Beyond Abuse agrees Ms Giddings should step-in.

"I think it's a very sad day for Tasmania and the fact that the Attorney-General is not doing anything about it is a ridiculous situation.

Ms Giddings told parliament yesterday she has confidence in the DPP.

She says it is important the decision on whether to lay further charges in the case remains separate from government.