The father of a Scottish backpacker murdered in Taupo 10 years ago is going to fight to keep her killer behind bars.

Brian Aim has spoken to UK media on the 10th anniversary of his daughter Karen's death and pledged to campaign against her murderer's bid for freedom.

That includes a vow to write to the Parole Board and state that her killer should not be released "for the safety of the public in New Zealand".

A video image of Karen Aim as she leaves the BP Service Station just before she was brutally attacked and latter died in hospital. (Photo / Supplied)

Karen Aim, 26, was backpacking through New Zealand when 14-year-old Jahche Broughton battered her to death with a baseball bat in the lakeside town on January 18, 2008.

The brutal crime, which appeared without motive, shocked both New Zealand and Britain.

The teenage killer, who just a few days earlier bashed another woman Zara Schofield so badly with a rock that she needed 30 stitches to her head, was sentenced to life imprisonment with a minimum non-parole period of 12-and-a-half years in 2009.

The New Zealand Parole Board today confirmed to the Herald that Broughton is eligible for parole in July 2020.

"Four months in advance of the hearing for Jahche Broughton, we will contact the registered victims and offer them the opportunity to make oral and/or written submissions if they wish to – as we do with all registered victims," a Parole Board spokesman said.

But Brian Aim says he still has no idea why his daughter was targeted and believes that Broughton should be kept behind bars.

"I wonder if he is safe to put back into society again, as he committed these two violent acts," the 61-year-old Orcadian told The Press and Journal newspaper.

"I feel it is my duty to write a letter to the parole board to try to keep him behind bars, for the safety of the public in New Zealand."

Karen Aim's killer Jahche Broughton stands in the dock at the Auckland High Court in 2009. (Photo / Glenn Jeffrey)

He told The Scottish Sun: "If it had just been Karen you could say it was just a random act. But he had tried it ten days before. I question whether he is safe to put out in society again."

Five years ago, Brian wrote to police to check on the progress of Broughton, to find out which prison Broughton is in, whether he is mixing with other prisoners and whether he is in rehabilitation programmes.

Aim told the Weekend Herald that he and his family had always wanted Broughton to take responsibility for his crime and tell them honestly how his daughter died.

"We wanted to find out from the one person who knew what happened that night as to whether Karen was chased and terrified before she was murdered or was she murdered from behind and never knew the incident ever happened?"

Aim tried to talk to Broughton after his sentencing but his mother, Eugenie Broughton, said he was not up to the pressure of a meeting.

The Aim family was overwhelmed with support after the killing, receiving a staggering 4600 sympathy cards.

"Those were a comfort, and now whenever I hear of someone else losing a child I make the effort to write to them or visit them," he told The Press and Journal.

"I can't say I know how they feel, but I can understand their feelings better than most and can offer them the same kind of comfort we received."