Natalie McGarry, the MP for Glasgow East, said this afternoon that her decision was taken "in the best interests of the party", but she maintained she had done "nothing wrong".
McGarry is being investigated as part of a probe into the finances of the Women for Independence campaign. The campaign first flagged over the summer that there were discrepancies between its donations and expenditures.
Because McGarry has temporarily removed herself from the SNP whip in Westminster, she will also seeing her SNP membership suspended while the investigation is being carried out.
An SNP spokesperson said tonight: "Natalie McGarry has taken this step in order to allow the full and proper investigation of the issue. She now hopes that the investigation can proceed as quickly as possible, is clear that there has been no wrongdoing on her part, and will not be commenting further until the matter is resolved."
McGarry's suspension marks the second scandal for the SNP in a matter of months.
In September, Michelle Thomson, the MP for Edinburgh West, also withdrew from the party after she became the subject of a police investigation into questionable property deals.