The party has confirmed reports that Mrs Ahmed-Sheikh, who is defending her Ochil and South Perthshire seat, is being investigated over what she says are “administrative matters”.
The Law Society of Scotland, the professional body for solicitors, has not commented.
Reports claim the investigation centres on the law firm Mrs Ahmed-Sheikh set up as a partnership in 2001, Hamilton Burns WS.
She resigned as a director of the firm shortly after becoming an MP in 2015. It emerged that Hamilton Burns was subject to a sequestration order by HMRC in December 2016.
Legal action was launched against the firm and Mrs Ahmed-Sheikh by HMRC, but did not go to court. She said at the time that she had “no outstanding personal tax liability whatsoever”.
Mrs Ahmed-Sheikh said: “I’m proud of my 17-year career in the legal profession. I am aware that issues have been raised with the Law Society in relation to administrative matters during my time at my former firm.
“The Law Society has a duty to uphold professional standards and they must be allowed to do so without prejudice.”
A spokesperson for the SNP said: “The party is aware that administrative matters relating to Tasmina’s time at her former firm are being looked into.
“Hundreds of issues are raised with the Law Society every year and it is right that they investigate them.
“She has co-operated fully and is continuing her campaign to be a strong voice for the people of Ochil and South Perthshire.”
James Kelly, Scottish Labour’s General Election campaign manager said: “Nicola Sturgeon must make it clear if she will continue to support Mrs Ahmed-Sheikh as an SNP candidate, and in the wake of a series of scandals it once again raises questions about the party’s vetting process.”
Conservative MSP for Mid Scotland & Fife, Murdo Fraser said: “These are serious allegations and, four weeks out from an election, the voters of Ochil and South Perthshire need an immediate explanation.
“It would be utterly unacceptable for the SNP to try and brush this under the carpet. For once, they need to be straight with people.
“If an investigation has been launched, then the SNP should do exactly as they did with their former MP Michelle Thomson and suspend Tasmina Ahmed-Sheikh immediately.”