Video report by Samantha Parker.
An HR director at nuclear site Sellafield "sat on" reports of sexual harassment by an employee, it has been alleged at a tribunal.
Consultant Alison McDermott has taken Sellafield, the Nuclear DecommissioningAuthority and HR director Heather Roberts to employment tribunal after she claims her contract was terminated when she blew the whistle on allegations of workplace harassment.
Ms McDermott, who runs company Interim Diversity Limited, was contracted to work at the nuclear fuel reprocessing and decommissioning site in Seascale, Cumbria, in 2018 but says her contract ended after she produced a report on the HR department.
At a hearing in Leeds on Wednesday, Ms McDermott, whose remit was equality, diversity and inclusion, said: "I was extremely concerned about issues I was unearthing in the HR function."
She said one employee was allegedly at risk of suicide.
The tribunal heard Ms McDermott had a conversation with Ms Roberts after an anonymous report making serious allegations of sexual harassment was made through Safecall, a confidential reporting system.
Ms McDermott said the report also described a "legacy of cover-up" around multiple allegations.
In her witness statement, Ms McDermott said Ms Roberts told her: "I've sat on this for weeks."
Being questioned by Deshpal Panesar QC, representing Sellafield and Ms Roberts, Ms McDermott accepted the Safecall report had only been received by Ms Roberts days before the conversation in September 2018.
But she said the HR director admitted the problem had been known for weeks and she had "sat on" it and taken no action.
She claimed Ms Roberts then asked her to take part in a covert investigation to "flush out" issues which were raised in the report, but she refused and advised her a formal investigation needed to be undertaken.
She said: "I was not prepared to do that and made that really clear."
Mr Panesar suggested she had agreed to take part in an undercover investigation, using focus groups to question staff.
Employment judge Philip Lancaster told the tribunal: "This, of course, is not a public inquiry into an alleged toxic culture at Sellafield and it is certainly not a forum to investigate specific allegations of improper behaviour on behalf of named individuals."
He said the panel would be concerned with identifying what disclosures weremade by Ms McDermott and what was said or done in response.
The tribunal, which is expected to last three weeks, will continue on Thursday.