An apprentice police worker accessed the force’s computer system to find out if her murder suspect brother was in prison with an undercover officer.
Naomi Jayne Buckland was ready to blow her colleague’s cover out of “misguided family loyalty”, a court was told.
The 22-year-old lost her job after following-through on her sibling’s plea for help.
Her brother Nathan was in custody awaiting trial for killing a man outside a pub in September 2018 when he begged her for information.
He was cleared of murder but convicted of the manslaughter of Iain Lee and jailed for eight years at his trial in March 2019.
The victim, 31, suffered a catastrophic head injury after he was punched to the ground in a bus stop in Newton Aycliffe in the September 2018.
The man died nearly two weeks later.
She only began working as a civilian apprentice with Durham Police in June 2018.
But Buckland had access to the force’s computer system, Durham Crown Court heard.
Days after her brother was arrested on suspicion of murder, she de-activated his Facebook account.
Prosecutor Sam Faulks said on October 22, 2018, she was asked to check if another inmate in the brother’s prison was an undercover police officer.
In a phone call to her brother in the jail, which was recorded, Buckland confirmed the inmate was not one of her colleagues.
Mr Faulks made clear it ultimately had no effect on the outcome of her brother’s case.
Naomi Buckland, of Newton Aycliffe, County Durham, admitted unauthorised computer access.
Mark Styles, mitigating, said she was of previous good character and “not the sort of person you expect to see before the court”, adding: “If there was a case of misguided loyalty to a family member, this was it.
“She was very close to her brother and the dire situation he was in led her to do what she did.
“As a result she lost her job and good name.”
Mr Styles said Buckland is now planning to re-train as a mental health nurse.
Judge Ray Singh told her: “This is very serious. The potential of what could have happened is immense.”
She was given a 16-month prison sentence suspended for two years and tagged for a four-month curfew.
A force spokesman said her behaviour “fell well short of the standard we expect and as such will not be tolerated by Durham Constabulary”.