The HSE has received assurances the late filing of Covid-19 data at the Mater Hospital has not been repeated elsewhere.
Earlier this month it was revealed 244 positive tests were added to a national database late, some of them dating back weeks.
HSE chief executive Paul Reid said an investigation into the incident has been completed and sent to the Department of Health.
He said there were issues with uploading data, but the Mater did its duty under the law.
Mr Reid said: "The Mater did meet their legal obligations on the reporting of cases, and all testing and tracing was completed in the process.
"The report does make recommendations in terms of validation of data.
"It also has got assurances from all of our other hospitals in terms of the correct uploading of data."
In a statement at the time, the Mater said it had reported all confirmed cases to health authorities on a daily basis and that it was working with the HSE to find out where the problem arose.
“At all times the Mater Hospital provided the information that the HSE required and met all legal requirements to report infectious diseases,” it said.
“All of this information is correct and up to date.
“We are working with the HSE to understand why the provided data may not have been accurately captured.”