A cop from the force under fire for its handling of the Nicola Bulley case is accused of gross misconduct in relation to the death of a young mum who was reported missing.
Kiena Dawes, 23, was reported missing just hours before she was hit by a train and pronounced dead at the scene last July.
Following her death, her family claimed she had been the victim of abuse which caused her to take her own life and claimed she was "let down" by Lancashire Police.
The police watchdog said an officer from the force now faces investigation because a man was released on bail after being arrested on suspicion of assaulting Kiena 11 days before she died. They add that this does not necessarily mean misconduct proceedings will follow.
The investigation is ongoing but the Independent Office for Police Conduct (IOPC) confirmed the unnamed officer has now been served notice and faces potential misconduct proceedings, though proceedings are not guaranteed..
Screaming children barricaded themselves in bedroom as thug strangled their mumAn IOPC spokesperson said: "Our investigation into prior contact between Lancashire Constabulary and Kiena Dawes, before her death on July 22, 2022 continues.
"We have been looking at the police response when Miss Dawes was reported missing, as well as reports that she had been the victim of assaults.
"Having obtained and reviewed a number of statements from witnesses, to understand the nature of the contact between officers and Miss Dawes, an officer has been served notice for gross misconduct in relation to their actions leading up to a man being released on bail earlier in July last year.
"This does not necessarily mean that misconduct proceedings will follow.
"Our thoughts remain with Miss Dawes' loved ones and all those affected by her death."
Kiena was reported missing after she disappeared on July 22 last year.
Her body was recovered from train tracks near the town of Garstang, Lancs., as friends and family conducted a frantic search for her in nearby streets and alleyways.
But before they could locate the missing 23-year-old, they got the terrible news that her body had been found on a rail line just after 1pm.
Lancashire Police confirmed a man had been arrested on suspicion of assaulting her, days before her suicide.
Despite the allegations, the man was released on bail pending further enquiries and no charges were brought against him.
University of Texas basketball coach fired after domestic abuse allegationHer heartbroken family claimed Kiena had been living in fear and had repeatedly sought the help of police in the weeks leading up her death.
They revealed shocking photos showing her looking bloodied and bruised following an alleged assault which happened after police had fitted panic alarms in her home.
Lancashire Police later confirmed a mandatory referral had been made to the IOPC, which probed if if the force acted sufficiently in response to reports of violence against Kiena and to locate her once she was reported missing.
IOPC regional director Catherine Bates added: "The death of Kiena Dawes is a tragedy that has had a devastating impact on her family and friends.
"Our thoughts remain with her loved ones and all those affected.
"Our independent investigation will help establish the actions taken by police, both in response to reports of violence and to locate her once she was reported missing.
"We have spoken to Miss Dawes' family to explain our role and will keep them updated on the progress of our investigation."
Kiena's older brother Kynan said after her death the force fitted her home with a panic alarm and given her a special neckless that had a button she could press.
But he said this hadn't stop her attacker coming to her home, before he allegedly split her head open, leaving her "completely traumatised".
And he said the police should have done more to help her as she attempted to bring her alleged attacker to court.
He said at the time: "The police have let my sister down, they have. She wanted to go through the legal route to get justice.
"The girl is dead now, but it should have gone to CPS ages ago. She didn't want to live a life the way she was living, so she ended it.
"They did not do enough. The head of CID is going to go through everything with a toothpick.
"They're going to find out why nothing happened, and why it got to the point where she felt she wasn't being looked after by the service, which she should be, and decided to take her life."
The force faced heavy criticism for the way it handled the Nicola Bulley case in nearby St Michael's On Wyre.
The force were slammed by critics for disclosing the nature of Nicola's issues with alcohol and the menopause.
This prompted a backlash from campaigners, MPs and legal experts, with some accusing the police of breaching her privacy.
A spokesman for Lancashire Police said: "First and foremost our thoughts are with Kiena Dawes' loved ones at this difficult time.
"We referred ourselves to the IOPC in July 2022 in relation to contact we had with Kiena before her death.
"The IOPC are currently conducting an independent investigation and as this remains ongoing it would be inappropriate to comment any further at this time."