Public Audit Committee convener Richard Leonard has sent an angry letter to the interim chief executive of Transport Scotland, describing such behaviour as “unacceptable”.
It comes after the committee received further evidence from Transport Scotland related to its inquiry into the construction of the CalMac ferries.
A report published by the committee on Thursday identified a series of failures in work to build the Glen Sannox and its sister ship, the as yet unnamed hull 802.
The contract for the construction of the vessels, which are intended to serve the island communities in the west of Scotland, was awarded to Ferguson Marine Engineering Ltd (FMEL).
But the ferries are now five years late while their a price tag has nearly tripled to almost £300 million.
The committee said the new evidence – which suggests former transport minister Derek Mackay was aware Transport Scotland intended to seek ministerial approval for awarding the contracts to FMEL – had been received too late to be included in its report.
Emails given to the committee dated from August 2015 show Mr Mackay wanted changes made to his comments in a news release in which First Minister Nicola Sturgeon announced the Clyde yard was the preferred bidder for the work.
In its report, the committee said it was “not convinced” the preferred bidder announcement was “necessary or indeed appropriate” – adding it “almost certainly weakened” the negotiating position of CMAL, the body which owns CalMac’s ferries.
In a letter on Friday to Alison Irvine, interim chief executive of Transport Scotland, Mr Leonard said the emails – which came to light following a freedom of information review – were part of information his committee had asked for in November 2022.
Mr Leonard wrote: “The committee believes it is unacceptable that this information has only just been uncovered, some four months after it was originally requested, and just one day after the committee finalised its report.”
He told Ms Irvine that MSPs are “disappointed that the same level of rigour involved in this FOI review was not applied to a parliamentary committee’s request”.
He continued: “It is also regrettable that it was not possible to include this new information in our report which was published yesterday.
“Had this evidence been made available when requested, it would have informed our report findings on the preferred bidder announcement.
“We therefore consider that the late receipt of this information has hampered our scrutiny work.”
A Scottish Government spokesman said it would study the findings of the public audit committee "carefully".
“Changes have already been put in place to address many of the issues raised,” the spokesman said. “This includes working with the shipyard’s senior management team to improve governance and accountability and revising processes for vessel procurement.”