A judge has said he was "troubled" after the Countess of Chester Hospital NHS Trust deleted potentially important evidence ahead of an employment tribunal, including documents relevant to the Thirlwall Inquiry into the crimes of Lucy Letby.
Former chief executive Dr Susan Gilby is suing the trust and its former chairman, Ian Haythornthwaite, claiming constructive unfair dismissal.
The tribunal was also told documents relevant to the Thirlwall Inquiry into the crimes of Letby had also been deleted from Dr Gilby's email account by her former employers - although these were later recovered.
In a ruling on a preliminary application, employment judge David Franey said the failure to preserve certain emails, messages and documents was "unexplained".
Dr Gilby was appointed medical director of the Countess of Chester Hospital NHS Foundation Trust in August 2018, a month after Letby was first arrested, and became chief executive in 2019.
She was suspended in December 2022 and gave notice of her resignation a few days later, although her contract ran until June 2023.
Dr Gilby said she had made a series of "protected disclosures" about then chairman of the board, Mr Haythornthwaite, who is named as a joint respondent in the claim.
After she accused him of inappropriate and bullying behaviour, she claimed he became "hostile" and "aggressive" and "co-ordinated" her suspension, the tribunal heard.
Both the trust and Mr Haythornthwaite deny the accusations and claim Dr Gilby's treatment was a "consequence of genuine and substantial performance concerns".
The tribunal heard that within a few days of Dr Gilby's suspension in December 2022, her solicitors put the trust on notice to preserve any relevant evidence - a normal legal procedure.
'Troubled'
After her claim was filed with the tribunal service, senior executives at the trust, including Mr Haythornthwaite and HR managers, were also ordered by the judge to preserve and disclose Whatsapp messages and emails relevant to her suspension.
However, the tribunal was told Dr Gilby later found that unknown staff at the trust had accessed her work accounts while she was suspended and deleted tranches of emails - including everything from before 24 October 2022.
She also found the Whatsapp application on her work phone had been deleted and she had been removed from a group with other executives, the hearing was told.
Judge Franey said he was "most troubled" by the fact that Mr Haythornthwaite had only disclosed a limited number of messages from his own work Whatsapp account and emails.
The judge wrote: "In principle he has most to gain from the destruction of material which helps the claimant’s case on causation."
The tribunal also heard Dr Gilby had been permitted full access to her trust email account in April this year, so she could prepare evidence for the Thirlwall Inquiry.
Dr Gilby was seeking two documents in particular, both of which she realised were missing from her inbox, and she also noted that her deleted items folder was empty, the tribunal was told.
In that case, the documents were found in July by IT specialists at the trust in a 'Retrievable Items Folder' .
However, any emails sent or received before September 2022 had been lost forever, the tribunal heard.
Judge Franey wrote: "The deletion on a selective basis of items from the claimant's work email account is troubling, and the wholesale deletion of the WhatsApp app and its content from her work mobile phone is unexplained."
He said the lack of significant disclosure of phone messages from head of HR Nicola Price, or from the Whatsapp account of Mr Haythornthwaite, was "surprising".
"I am satisfied that in relation to these matters there has been unreasonable conduct of the proceedings by the respondents," he said.
However, Judge Franey denied an application by Dr Gilby to have the response to her claim struck out without a full tribunal.
He wrote that he was satisfied a fair trial could take place, and that the tribunal could "draw appropriate inferences" from the missing documentation.
The case is listed for a 20-day hearing in November.
A spokesperson for the hospital trust said it would not be appropriate to comment while tribunal proceedings were ongoing.