A prisoner was kept in isolation for more than 800 days at the north-east’s super jail.
Figures released by the Scottish Prison Service (SPS) revealed one HMP Grampian inmate was put in solitary confinement for 809 days.
The man was first subject to “removal from association” in October 2014 and was not released into the general population until the beginning this year.
He spent a total of two years and three months on his own, with little or no contact with fellow prisoners.
The SPS declined to identify him or elaborate on the reasons he was segregated for so long.
In 2015, murderer Imran Shahid, who is now interned at the Peterhead site, won a court battle over the amount of time he had been forced to spend in solitary, for his own protection.
The Supreme Court ruled Shahid – who is serving a minimum of 25 years for murdering Glasgow schoolboy Kriss Donald in 2004 – had his human rights violated.
He had been kept continuously in solitary confinement for 14 months at prisons across the country.
The SPS has said isolation, known as “removal from association”, is only used in exceptional circumstances.
Governors need special permission from the Scottish Government to keep a prisoner in solitary for more than 30 days at a time.
Last month the Press and Journal revealed that Shahid was suing the prison governor Allister Purdie after his sex aid was confiscated.
He claims he suffers from “erectile disfunction” and needs a pump to treat it because of the side effects of drugs like Viagra.
The killer is also demanding staff return his internet-enabled games console – or £3,000 in compensation.
The Xbox 360 was taken from him over fears he could access the internet while behind bars.
