Kemi Badenoch has accused the SNP of a ‘cover-up’ over the Peter Murrell scandal – and demanded Westminster launches its own inquiry.

The Tory leader condemned the Nationalists and Greens for uniting to reject a Holyrood probe into the fallout from the £400,000 embezzlement of SNP funds by Nicola Sturgeon’s estranged husband.

She also said that Westminster’s powerful Scottish Affairs Committee must now launch its own investigation into issues like whether public money was involved and the decisions made by prosecutors in the case, including why the guilty plea only happened after last month’s Holyrood elections.

In an interview with the Mail during a campaigning visit ahead of Thursday's crunch Aberdeen South by-election, Mrs Badenoch condemned MSPs for voting against holding a full inquiry into the fallout from the Murrell case last week.

She said: ‘It’s a cover-up, is there another word for it? It’s a cover-up. If there’s nothing wrong done then why not have the inquiry?

‘The fact that so much was able to happen for so long and nobody saw or heard anything – Nicola Sturgeon certainly didn’t see anything even with all the campervans and coffee makers arriving in her house – shows that probably more people knew what was going on. We should investigate.

‘£400,000 is a hell of a lot of money, we need to know whether public money was involved, for instance. Just sweeping it under the rag and hoping they can put all the blame on Peter Murrell and the problem goes away is not the answer.’

Last week, the Scottish Affairs Committee delayed a final decision on whether to launch a probe.

Asked whether it must now hold an inquiry, Mrs Badenoch said: ‘Yes. We should not allow the cover-up to stand. If Holyrood won’t look at it, Westminster should.’

She said her MPs on the committee will push for an inquiry and highlighted that she previously pushed for Westminster to block the SNP’s gender reforms when she was in government and ‘made sure that happened’.

Mrs Badenoch said: ‘We want Scotland to be run well and somebody needs to speak up for the people of Scotland, just as we are speaking up for Aberdeen, so we will do everything we can.

‘I think that it’s important for Labour to also show that they care about probity so this is not an issue that only Conservatives should be interested in. 

'We are the ones who are flagging the problem but everybody should care about this.’

She also raised concerns about the role of the Crown Office and Procurator Fiscal Service in the Murrell case, saying: ‘It is quite clear that they didn’t want it to impact the Holyrood elections.

‘One of the things that we want to see happen is splitting the role of the head of the prosecution service and the Lord Advocate. That will help – I think the fact those two roles were combined meant that this did not come out even sooner.’

At First Minister’s Questions Scottish Labour leader Anas Sarwar said institutions like the Crown Office, Police Scotland, HM Revenue and Customs and the Scottish Legal Aid Board must face questions on ‘why a wealthy man who owns property abroad and says he has the means to immediately pay back £400,000 had access to legal aid’.

Mr Sarwar later said that if ‘legitimate questions’ are not asked of institutions during the independent review ‘then if Westminster and the Scottish Affairs Committee has to ask those questions then they should legitimately ask those questions if they are legitimate questions’.

But First Minister John Swinney said his party was ‘the victim of an embezzlement’ and opposed an independent inquiry or parliamentary inquiry into the issue.

During a campaign event at the home stadium of Cove Rangers Football Club, Mrs Badenoch said voters in the Aberdeen South by-election can punish the SNP for its handling of the scandal.

She said: ‘I think many voters have been scandalised by the revelations that have come out of the whole saga with Peter Murrell. John Swinney’s hands are not clean on this; he first appointed him.

‘So this is an SNP scandal and what we’ve been hearing on the doorstep is not just the fear for oil and gas but also how disappointed people are with the SNP.

‘So it is an opportunity – if they are annoyed with the SNP, if they are upset with the SNP, then they should not let the SNP candidate win in Aberdeen South and the only way to stop that is to vote for Douglas Lumsden.’

The court heard that discussions between Mr Murrell and his legal representatives, and with the Crown, about a guilty plea ‘took some time and continued until just prior to the case calling on 25 May’ and that the plea was intimated to the Crown on May 21.

The SNP has been asked for comment.