Netflix has unveiled the official release date for its upcoming true crime documentary, The Investigation of Lucy Letby, which features never-before-seen footage.

The Netflix documentary shines a light on the case of Lucy Letby, who was convicted of the murder of seven babies as well as the attempted murder of seven more.

Unheard insider accounts from those closest to the case reveal "harrowing and divisive" details, with insight from the detectives who built the case, the families seeking answers, the hospital consultants who initially raised the alarm, and lawyers and medical experts who question the evidence.

The Investigation of Lucy Letby airs on Netflix on February 4, and a trailer has already been released, which shows never-before-seen footage of Letby's arrest as she is heard telling her family: "Don't look, please go in."

Experts hail it a "once-in-a-generation type case" as the trailer explains how babies kept dying, while Letby had a "central role".

The trailer continues to highlight the concerning pieces of evidence found by investigators, including a note which reads "I killed them on purpose."

Netflix described the case as "one of the most controversial of our time", as it includes exclusive testimonials from people who claimed "things were not so straightforward".

During a police interview shown in the trailer, Letby is heard breaking down as she says: "I feel like I have only ever done my best for those babies", with an expert claiming "there was no motive, none".

The 90-minute documentary details the crimes committed between June 2015 and June 2016 at the Countess of Chester Hospital.

Netflix said of the documentary: "The trial gripped Britain and her conviction has divided opinion.

"The feature-length documentary includes, for the first time, new materials and testimony from the British police who investigated the case and never-before-seen footage of Letby during her arrest and questioning.

"The documentary also includes contributions from the mother of one of the victims speaking about her experiences and involvement in Letby's trial. This is the first time that a family member involved in the prosecution has spoken in a documentary.

"The film includes interviews with experts and lawyers on both sides, giving the most comprehensive look at one of Britain's most notorious crimes."

In July 2024, Letby was sentenced to her 15th whole life term after being found guilty of the attempted murder of another girl, known as Baby K, following a retrial.

The Investigation of Lucy Letby airs on Netflix on February 4