The MP, Pavel Gamov, was asked to resign from his post in the party, and if he refused, he risked expulsion, the Sweden Democrats said on Friday. Later in the day they confirmed he had chosen to leave voluntarily.
This makes him the latest of several Sweden Democrats who have either left the party to become a political independent, taken a 'time-out' from their roles, or quit parliament altogether.
It was not immediately confirmed whether or not Gamov was to stay in parliament as an independent MP.
The reason is a trip Gamov made to Russia in September, sponsored by a close acquaintance of Russian President Vladmir Putin, against the will of the Sweden Democrats. He had initially told Swedish media that a small Polish organization had funded the trip.
During the visit, he observed a regional election and reportedly told Russian media he was "impressed by Russia's vote-counting machines".
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A fellow party member who was also on the Moscow visit has also accused Gamov of repeatedly harassing her during the trip.
Reached by Aftonbladet, the woman confirmed that she had filed a report with the party but declined to comment further.
In a press release, Mattias Karlsson, who is the group leader of the Sweden Democrats in parliament, said: "Pavel Gamov has acted in a manner incompatible with the role of parliamentarian. A party can not remove a member of parliament from his office against his will."