Questions about Lucy Letby’s boyfriend have resurfaced after the doctor at the center of one of the most discussed personal relationships in her criminal trial was publicly identified for the first time.
Dr Mark Deakin, a paediatric doctor who worked alongside Letby at the Countess of Chester Hospital, had previously been protected by a court anonymity order. During Letby’s trial, prosecutors repeatedly questioned her about their closeness, while evidence revealed extensive communication between the pair.
Deakin died in July 2026 at the age of 53. Following his death, the Court of Appeal lifted the order preventing his identification on September 2, 2026.
Despite frequent descriptions of Deakin as Letby’s alleged “boyfriend,” one fact is crucial: Letby denied that the pair were romantically involved.
Who Was Mark Deakin?
Mark Deakin was a paediatric doctor who worked at the Countess of Chester Hospital during the period when Letby was working as a neonatal nurse.
He later continued his medical career at Alder Hey Children’s Hospital in Liverpool, where he became a consultant.
Deakin was married and a father of two.
His identity became relevant to the Letby case because of his close communication with her and the evidence he subsequently gave during her criminal trial.
Until September 2026, reports could not identify him because of legal restrictions.
Following Deakin’s death, those restrictions were lifted, allowing British media organizations to name him publicly.
Were They Dating?
It has never been established that Lucy Letby and Mark Deakin were formally boyfriend and girlfriend.
During her trial, prosecutors questioned Letby extensively about whether she had romantic feelings for the doctor.
Letby denied that Deakin was her boyfriend.
She also rejected suggestions that she had a crush on him, although messages presented in court showed friends teasing her about the apparent closeness between them.
When asked about Deakin, Letby said she eventually came to “love” him as a friend.
That distinction is important. While headlines and courtroom questioning have frequently used the term “boyfriend,” there was no confirmed public relationship between them.
Their Messages
The volume of communication between Letby and Deakin became a significant point of interest.
Evidence later heard by the Thirlwall Inquiry revealed that the pair exchanged more than 1,300 Facebook messages during a period in 2016.
The messages were exchanged after senior doctors had raised concerns about Letby’s association with unexplained deaths and collapses on the neonatal unit.
The Inquiry heard that Deakin supported Letby while she pursued a grievance against the Countess of Chester Hospital.
He later acknowledged that he had not understood the complete clinical picture surrounding the concerns about her.
Giving evidence to the Inquiry in October 2024, he said he believed he may have been misled or manipulated while providing that support.
Courtroom Moment
Deakin’s appearance during Letby’s criminal trial also attracted attention because of her visible reaction.
When he entered court to give evidence, Letby became emotional and attempted to leave the dock.
Prosecutor Nick Johnson KC later questioned her about that reaction and referred to Deakin as her boyfriend.
Letby rejected the characterization.
She said her reaction was because she felt unwell rather than because she was upset about hearing him give evidence.
The exchange became one of the most widely reported personal moments during a trial otherwise dominated by extensive medical and clinical evidence.
A Hospital Placement
Their connection continued after Letby was removed from frontline neonatal duties.
The Thirlwall Inquiry heard that Deakin helped arrange for Letby to make observational visits to Alder Hey Children’s Hospital.
Letby had been moved from clinical duties at the Countess of Chester in July 2016 following concerns raised by consultants.
Despite those circumstances, Deakin subsequently helped facilitate visits to Alder Hey while supporting her professionally.
The Inquiry heard that senior managers at the hospital had not been made aware of the circumstances surrounding Letby’s removal from neonatal work.
Deakin later described his involvement as a major mistake and expressed regret about his actions during that period.
Confidential Information
Another serious issue concerned patient confidentiality.
Evidence examined during subsequent proceedings showed that Deakin and Letby communicated about patients.
The Thirlwall Inquiry heard that the mother of Child N, one of the babies Letby was convicted of attempting to murder, had complained about the doctor discussing her son’s medical condition in messages.
Deakin acknowledged during the Inquiry that, with hindsight, the messages were inappropriate.
He also accepted that parents would understandably find the discussions upsetting.
The issue later became significant professionally for Deakin.
Deakin Was Dismissed
Deakin was dismissed from Alder Hey Children’s Hospital on June 23, 2026, following an investigation into his conduct.
According to reporting following the lifting of his anonymity, disciplinary proceedings examined his communications with Letby and breaches involving confidential patient information.
The investigation also considered his involvement in arranging observational visits for Letby.
He was found unconscious in his car the following day and later died. He was 53.
An inquest into his death is pending.
Why His Name Was Hidden
For years, the public knew Deakin only through anonymous labels.
During Letby’s criminal proceedings, he was commonly referred to as “Dr A.” At the Thirlwall Inquiry, he appeared under another anonymized designation.
A court order prevented the media from publishing his identity.
That changed following his death.
On September 2, 2026, the Court of Appeal lifted the anonymity order, concluding that the justification for continuing to conceal his identity no longer applied.
His identification consequently generated a fresh wave of coverage surrounding his connection to Letby.
Who Is Lucy Letby?
Lucy Letby is a former neonatal nurse who worked at the Countess of Chester Hospital.
She was convicted in 2023 of murdering seven babies and attempting to murder six others.
A retrial in 2024 resulted in an additional conviction for the attempted murder of another baby.
She is serving whole-life orders, meaning she is not expected to be released from prison.
The Thirlwall Inquiry was subsequently established to examine events at the Countess of Chester Hospital and how concerns surrounding Letby were handled.
Its final report is scheduled to be published on September 15, 2026.
Was He Her Boyfriend?
The most accurate answer to the question “Who was Lucy Letby’s boyfriend?” requires some caution.
Dr Mark Deakin was the married doctor prosecutors questioned Letby about and whom some reporting described as her alleged boyfriend or crush. The pair communicated extensively, and their friendship continued during the period after Letby was removed from frontline clinical duties.
But Letby herself denied that Deakin was her boyfriend.
She also denied being romantically attracted to him and characterized their relationship as a close friendship.
No confirmed romantic partnership between the two was established publicly.
What is documented is that they had a close relationship, exchanged a large number of messages and remained in contact during a crucial period in the events later examined by the Thirlwall Inquiry.
Deakin’s identification in September 2026 finally puts a name to a figure who remained anonymous throughout years of reporting about the Lucy Letby case.
It does not, however, turn an alleged romance into a confirmed one. For that reason, Dr Mark Deakin is most accurately described as Letby’s former doctor colleague and close friend who was repeatedly characterized during the case as her alleged “boyfriend.”
