The family of Suzanne Pilley’s murderer has demanded the case against him be reexamined by a different police officer.
Ms Pilley, 38, disappeared from Edinburgh on her way to work on May 4 2010.
It is believed she was murdered in the basement of Infrastructure Managers Ltd in Edinburgh and her body buried in a forest in Argyll.
Her ex-boyfriend David Gilroy was found guilty of her murder and Ms Pilley’s body has never been found.
Gilroy, now 57, is serving a life sentence with a minimum of 18 years.
For the ten-year anniversary of Ms Pilley’s disappearance on Monday, Police Scotland launched a fresh appeal to find her body.
Benny and Linda Gilroy – the murderer’s father and step-mother – maintain his innocence and have now written to Police Scotland chief constable Iain Livingstone.
They accused police of not allowing their own expert reasonable access to CCTV footage used in the trial.
In the letter, the family wrote: “How can the original officer have a truly open mind about this even if he wanted to?
“If he produced flawed evidence, he is hardly going to have the motive to expose that to public scrutiny.
“The flaws we wish our expert to check against the original footage are most obvious in relation to what was taken from cameras in and around St Andrew Square, Edinburgh.
“Although we do also believe some further work on the Argyll footage could show where the police report about that was misleading.”
The Gilroys added: “We would also like to say that if we thought for one minute that David committed such a heinous crime, we would certainly be asking him to put the Pilleys’ minds at rest.”
A Police Scotland spokesman said: “We can confirm we have received a letter, sent to the chief constable, and it will be replied to in due course.”