Nicola Sturgeon has refused to name to the SNP consultant who met with the controversial political consultancy accused of harvesting the Facebook data of millions of users.
The First Minister instead told MSPs that the Tories were "mired" in links with Cambridge Ananlytica and insisted the SNP had done nothing wrong after it met with the firm.
The SNP has been on the backfoot since a former director of the firm revealed this week that a meeting was held with the SNP - after weeks of Nationalist criticism of Tory links to the company.
Read more: SNP accused of hypocrisy over links to Cambridge Analytica
Tory leader Ruth Davidson hit out at the SNP's lack of transparency at First Minister's Questions
Ms Davidson said: "The SNP have raised sanctimony to an art form, but what stinks here is the reek of hypocrisy.
"When it comes to dealings that others have had with Cambridge Analytica, the First Minister and her party have spent weeks demanding full transparency - yet when it came to the SNP it took a whistleblower, giving evidence in a Parliamentary committee before facts even began to be dragged out into the open."
Ms Davidson demanded to know the identity of the SNP consultant who met with Cambridge Analytica in 2016, as well as the exact date of the meeting and where it took place.
But Ms Sturgeon said: "I am not going to name someone who has done nothing wrong, who was working for the SNP as a consultant, in order that a witch-hunt can be carried out into that person."
Read more: Former Cambridge Analytica director says company met SNP
The First Minister said that after the meeting, the SNP decided against working with Cambridge Analytica and judged the firm to be "cowboys."
But Ms Sturgeon told MSPs that the Conservatives have accepted donations from a director of Cambridge Analytica's parent company SCL.
A former chair of the Oxford Conservative Association used to run SCL, Ms Sturgeon added, while SCL's founding chairman is an ex-Tory MP.
The UK Government has also had a "close working relationship" with SCL, Ms Sturgeon said, while the Ministry of Defence paid them £200,000, the SNP leader added.
Ms Sturgeon added: "The SNP has never worked with Cambridge Analytica and the Scottish Government has never worked with Cambridge Analytica. I'm not sure the Conservative party or the UK Government can say the same thing."