MSPs have questioned the reappointment of the chair of the Scottish Housing Regulator in the midst of a parliamentary investigation sparked by damning evidence about the culture and practices of the quango.

The SHR, which is accountable to the Scottish Parliament, announced the reappointment by the Scottish housing minister Margaret Burgess of chair Kay Blair less than a week after the body received a six-page letter from the Parliament's infrastructure and capital investment committee, seeking answers to questions about the regulator's conduct towards housing associations.

Alex Johnstone MSP, a Scottish Conservative member of the committee said: "The SHR seem to be operating in a very closed environment, they are not reacting in any way to the criticism they receive, and certainly not positively. I do have concerns they are carrying on regardless which does not bode well for the future."

"They seem to be in denial. I can't say at this stage whether I think [SHR board members] should be reappointed or not, but I would have preferred that they answered the questions the committee have posed to them first. It's an interesting set of circumstances."

A Scottish Government spokesman said that the timing of the re-appointment, and the appointment of two new board members for four year terms was "determined by the expiry of their first terms of appointment on 31 March 2015", and unaffected by the parliamentary probe. "Ministers make appointments solely on the basis that they comply with the Code of Practice for Ministerial appointments to Public Bodies in Scotland". He said.

Evidence given in the committee's open session last November included some of strongest criticisms ever levelled at a public body in the Scottish Parliament, including the charge that the regulator was creating a "climate of fear", that it was exercising "unchecked powers" and acting "against natural justice".

In its letter to the regulator's chief executive Michael Cameron, received days before the appointments were announced, the committee asked a series of questions based on the evidence, some given in closed session at the request of housing associations who did not want to be revealed as critics of the regulator.

The SHR was given a month to respond to the letter, a period which elapses on Wednesday.

Issues that the committee is seeking to explore include alleged lack of proportionality, alleged presumption of guilt on behalf of housing associations, a "culture of mistrust", lack of the right of appeal against regulatory judgements, and improved oversight of the financial problems of social landlords.

The last question relates to the Dumfries and Galloway Housing Partnership (DGHP) scandal, where the SHR has defended its retrospective approval for the award of a £77m public contract to a heavily indebted local builder without checking current accounts or seeking bank references, partly on the grounds that the whistleblower who raised the issue with them, while a DGHP tenant, did not himself live in one of the houses built by the now defunct contractor.

Mike Mackenzie, an SNP committee member who worked in the construction industry for 35 years told the Sunday Herald that while the complaints raised against the regulator's conduct were significant, "fair play and natural justice" demanded that the SHR be given time to respond.

However, he criticised the evidence of Michael Cameron on the DGHP affair saying: "I have never known a situation where a builder goes into liquidation when there isn't significant disruption or even chaos, both financially and in terms of quality control."

"For the SHR to say that there is no issue because we haven't had a response from tenants strikes me as a pretty glib response. Construction is a complicated business, and to rely on tenants reporting faults as your quality control mechanism is poor control."

"Given the scope of the concerns that have been raised, with reference to the generality of the concerns raised by committee, perhaps the regulator should have postponed the re-appointment of the new chair."

However SNP MSP Jim Eadie, the committee's convenor told the Sunday Herald that he saw "nothing untoward" in the timing of Blair's reappointment, and said there was "no suggestion that [the SHR] was being anything other than co-operative with the enquiry."

Insisting that he was "not pre-judging the process" he added: "If we felt they weren't co-operating with the level of detailed information we are seeking, there would be others avenues open to us that could make life uncomfortable, and we would need to reflect on that."

A spokeswoman for the SHR said: "Our board members are appointed by the Scottish Government following an open public appointments process. You should address any queries to the Scottish Government."