Irish politicians hit out at Gabriel Makhlouf's appointment to head of Central Bank

Irish politicians say they're concerned New Zealand Treasury Secretary Gabriel Makhlouf will become the country's next Central Bank governor amid the Budget "hack" scandal.

Last week, Makhlouf said the Treasury had been systematically hacked only hours after the National Party revealed it had access to Budget information.

But Treasury later admitted that it hadn't been hacked and someone had only "exploited a feature in the website search tool" which "does not appear to be unlawful".

Public statements made by Makhlouf are now under investigation by the States Services Commissioner.

Pearse Doherty, finance spokesperson for left-wing Irish republican party Sinn Féin, told The Irish Times Makhlouf should not start his role with the Central Bank until the investigation has concluded.

Doherty said it "wasn't a small issue".

"We need to make sure that someone in the highest position in the Central Bank has proper judgement," he told The Irish Times.

It was also revealed on Friday that Treasury had been advised by the National Cyber Security Centre (NCSC) to refer the matter to the police for assessment last Tuesday as the data breach, as described to the NCSC, did not appear to involve Treasury's network being compromised.

The NCSC's role is to protect systems from advanced cyber threats.

Ireland's Fianna Fáil party member Michael McGrath has also reportedly sent a letter to the Irish Finance Minister.

"The governor of the Central Bank is one of the most sensitive and important roles in our States," the letter says.

"It is vital we have full confidence in the holder of the office."

New Zealand National Party leader Simon Bridges said heads needed to roll for what was "either gross incompetence or dirty politics", which he described as sitting on a lie "quite consciously".

"Makhlouf's position is clearly untenable. He went out and put out a statement, having been told by GCSB that there was no systematic hacking, that there was," Bridges told The Am Show on Wednesday.