The report was completed last Friday and sent to the office of the Taoiseach.
Following approval by the Taoiseach and Minister for Health Simon Harris, a review by consultancy firm PricewaterhouseCoopers (PWC) looked into the cost overruns at the National Children's Hospital.
The review is now complete, and it has found that there was failings around budgeting and planning on the project.
According to
RTÉ, the report criticised the hospital board and says some red flags around the spiralling costs were missed.
The report identified a major underestimation of costs, but says that it was too late to re-tender when the €400m overrun became clear.
This overrun led to the hospital not being built as it would have increased costs even further.
The report is yet to be published, but looks set to be released "soon".
Back in February, Taoiseach Leo Varadkar said that the Children's Hospital review would "identify those responsible for cost overruns".
However, while the review did examine individuals' roles, it will not name anybody directly.
On Monday, Varadkar said the Children's Hospital would now be up and running by 2023.
