SNP chief executive Peter Murrell has been urged to explain what action party officials took to satisfy themselves that Michelle Thomson would make a suitable MP.
Labour has demanded answers from Mr Murrell following the revelation that Mrs Thomson’s lawyer has been struck off after acting for her in a string of residential property deals.
Jackie Baillie, Labour’s public services spokeswoman, has outlined her concerns in a letter to Mr Murrell, who is also the husband of SNP leader Nicola Sturgeon.
Ms Baillie wants to know at what point Ms Sturgeon and other SNP figures knew of Ms Thomson’s property transactions.
Earlier this week Mrs Thomson resigned the party whip at Westminster after police launched an investigation into the property deals conducted by her lawyer.
Mrs Thomson has maintained her innocence and said she will co-operate with the Police Scotland investigation.
In a separate move Ms Baillie has called on the Lord Advocate, Scotland’s most senior law officer, to make an urgent statement to Holyrood on the matter.
Ms Baillie said the Lord Advocate Frank Mulholland needed to make a statement to address concerns about the Crown Office’s handling of the case and why it had only come to light now that Mrs Thomson’s solicitor Christopher Hales had been struck off.
In her letter to Mr Murrell, Ms Baillie said: “At the heart of this scandal are vulnerable families who have been taken advantage of by an SNP politician more interested in making money than helping people. In public the SNP talked about helping those in need whilst in private one of their leading voices on business was making life miserable for vulnerable families.
“We need to know from the SNP who knew what and when. At what point did Nicola Sturgeon and senior SNP officials first become aware of this situation and what did they do about it?
“The reputation of politics isn’t high at the best of times. We need full transparency from the SNP on this scandal.”
Police Scotland has revealed that it has been instructed to investigate “alleged irregularities relating to property deals in the year 2010/11” raised in a Scottish Solicitors’ Discipline Tribunal (SSDT) hearing against Hales.
Speaking about the need for a statement to Parliament by the Lord Advocate, Ms Baillie said: “There must be a full and thorough investigation into these allegations. The public would find it unacceptable if the establishment closed ranks to protect one of their own.
“We need a full statement in Parliament from the Lord Advocate. There are already concerns about how the Crown Office has handled this case. We need to know what action was taken when the Law Society of Scotland first ‘informally’ made the Crown Office aware of its concerns about Michelle Thomson’s property deals in December 2014 and then formally in July 2015. We also need to know whether there were any delays between when the Crown Office was first made aware of the allegations and when it instructed Police Scotland to investigate. Nothing short of full transparency will be accepted by the public.”