An outbreak of Covid-19 at a care home has been linked to an employee who allegedly hid her positive test result from managers.
A major investigation has now been launched at the residential home in Dublin.
An elderly female resident in her 70s and a staff member at the home have also been infected.
Along with the three confirmed cases, another four staff members and residents have been in isolation for 11 days.
The care home management ordered the lockdown on Monday, August 17, after finding that the worker had continued looking after residents, despite knowing she was infected.
The worker took the Covid test on Wednesday, August 12.
She had been contact traced by the HSE after her son, a meat factory worker, had tested positive for the virus.
It is understood the care worker was informed of her positive result three days later while she was working a weekend shift caring for two residents.
Sources say the worker did not tell her manager of the results and continued working until the Sunday.
The issue came to light the following day when the worker was asked to work overtime.
It is understood that she said she couldn't, as a relative had tested positive for coronavirus, but she did not tell her manager of her own result.
The manager told her to contact her GP to arrange a test.
The care home's Covid-19 supervisor later contacted the worker who, when questioned, admitted she was infected.
A source said: "A containment and deep clean operation was immediately put in motion and everyone in the house concerned was tested and all contact tracing completed."
The families of the residents were informed, and the house is now in isolation.
The care home management team was seriously concerned as to why the HSE tracing system failed to inform them of the worker's test result.
An investigation found that the testing centre was not given details of the care home where the individual worked.
Sources say that the matter will be referred to the gardaí.
Meanwhile, the possibility of an early lifting of the semi-lockdown in Kildare, ahead of September 6, will be decided today.
Health Minister Stephen Donnelly said an early reprieve from the measures imposed in the county - sparked by major outbreaks in factories - will be reviewed at a meeting of the National Health Emergency Team (Nphet).
He was speaking before it was announced yesterday evening that another 164 people have been diagnosed with Covid-19 nationally, with 22 in Kildare.
Dublin topped the number of new cases with 93.
"There is a very difficult call for Nphet to make," Mr Donnelly said, in response to Kildare Fianna Fáil TD James Lawless at the Special Committee on Covid-19 Response.
Nphet will have to judge if the cases are low enough to have reduced community transmission.
"The cut-off point for Ireland's green list was no more than five per 100,000 over the previous two weeks. Kildare was at nearly 200 per 100,000. It was very high," he said.
Earlier, acting chief medical officer Dr Ronan Glynn said the early escape from restrictions in the county was under review.
Some 65pc of those newly infected are under the age of 45 years.
Dr Glynn said there have been two particular instances of Covid outbreaks linked to sporting fixtures.