A report has suggested it is “very plausible” that fees paid by RTE to its star presenter Ryan Tubridy were underdeclared by 120,000 euro from 2017-2019 to keep the payments under the 500,000 euro mark.

Tubridy’s earnings were stated by RTE as 491,667 euro for 2017, 495,000 euro in 2018 and 495,000 euro in 2019 when his fees were actually 511,667 euro, 545,000 euro and 545,000 euro respectively.

The Grant Thornton report published on Wednesday said there was no document to explain why the 120,000 euro (£103,100) end-of-contract fee was split across 2017, 2018 and 2019.

Calculations carried out by a specialist forensic accountant who authored the report concluded that the 20,000 understatement in 2017 followed by the 50,000 euro under-declaration in 2018 and 2019, matched closely to the minimum amounts needed to bring the fees under 500,000 euro.

The report concluded: “Having conducted my exercise, on the balance of probabilities, I find that in the absence of any other further explanations, my hypothetical exercise (which assumed the adjustments were made with an RTE objective to achieve a position where the ‘revised earnings’ for each year 2017, 2018, and 2019 were all below 500,000 euro) provides a very plausible explanation as to how the values of the adjustments of 20,000 euro, 50,000 euro and 50,000 euro were calculated or allocated by RTE for 2017, 2018, and 2019 respectively.

“Whilst my exercise provides a very plausible explanation, (it) is not possible to be conclusive without having met all individuals to date,” it states.

Former RTE director general Dee Forbes and director of content Jim Jennings are named as two individuals who were not interviewed for the report and have not commented on it.

The publication of the report is the latest development in the controversy surrounding RTE’s financial and accounting practices as well as governance at Ireland’s public service broadcaster.

Tubridy welcomed the findings of the report that he did not claim the 120,000 euro exit fee, and the conclusion that he had “no involvement” in how his published earnings were adjusted by RTE.

“I repeat my offer to publish the details of any future RTE contract,” he said.

The chairwoman of the broadcaster’s board, Siun Ni Raghallaigh, said the findings confirmed concerns about a “siloed management culture”, “poor internal communication and weak processes”.

Media minister Catherine Martin called the findings in the report “deeply concerning” and said it highlighted “further lapses in governance and failure of proper internal controls and processes” within the state broadcaster.

Public Accounts Committee chairman Brian Stanley called for current and former executives to appear before a further hearing, saying the Grant Thornton report underlined “severe levels of concealment that senior management in RTE went to in order to mislead the public and the Oireachtas”.

The report also states that RTE acted correctly and appropriately when it stated in June that it had underdeclared fees to Tubridy, already its highest paid presenter, by 345,000 euro (£296,400) from the years 2017-2022.

The under-declaration of 225,000 euro (£193,200) over the years 2020-2022, was related to RTE’s decision to underwrite the payments, which effectively resulted in the publicly funded broadcaster stumping up to cover the costs legally due to Tubridy.

Three 75,000 euro (£64,400) annual payments were received by Tubridy for proposed public appearances for Renault, as part of a tripartite agreement involving the sponsor, RTE and the presenter.

RTE issued a 75,000 euro (£64,400) credit note to Renault for the first year in exchange for the motoring company paying Tubridy, and in years two and three, when Renault was no longer involved, it paid Tubridy from its own funds using a UK-based commercial barter account.

This aspect of the fees was examined in a Grant Thornton report that was completed in June.

The Grant Thornton report published on Wednesday found there were “several failings” that led to Tubridy’s fees for 2017-2019 being incorrectly stated.

It said that three Deloitte reports were submitted to RTE’s finance department but do not appear to have been submitted to the RTE Board.

Reacting to the report, Ms Ni Raghallaigh said: “Regrettably, this report confirms our view of the siloed management culture that has prevailed in RTE and supports the decision by the board to initiate an ongoing programme of corrective action.”

She said the report paints a picture “of poor internal communication and weak processes”, and outlines dates where “errors could have been corrected but were not”.

“It is also clear from the report that the then Executive did not properly engage with the board on these matters, nor was relevant information provided to the board by the Executive or by the auditors.”

She added that the issues highlighted in the report will be raised with RTE’s auditors, Deloitte, and said steps “have been taken to ensure there can be no repeat of these failures”.