The complaint follows a four day court hearing in June that ruled there was no evidence of voting manipulation but decided the election must be re-run anyway due to irregularities in vote counting.
Now independent Alexander van der Bellen, who won by 0.6% of the vote in the first presidential election run-off on May 22nd, will once again go up against the Freedom Party candidate Norbert Hofer on October 2nd.
At the weekend Hofer filed the latest complaint regarding the election and their “concrete suspicions” about the voting ballots being ordered en mass to care homes.
Lawyer for the anti-immigration party Dieter Böhmdorfer told the Kurier: “We have received some pieces of evidence and are also continuing to accept them. We will calmly examine them and pass them on to the state prosecutors.”
The Constitutional Court hearing in June confirmed one of the Freedom Party's initial complaints that some postal votes were counted too early and votes were sometimes counted by the wrong people.
The court decided that the irregularities would have affected around 70,000 votes and - with only a difference of 30,863 votes between the two candidates - ruled the election must be re-run.
The Freedom Party have responded by arguing that although no evidence of deliberate fraud was found it does not mean that no manipulation took place.
It is not the first time voting in care homes has been brought into question by the Freedom Party. In 2015 the Constitutional Court voided two mayoral elections in Vorarlberg because of the party's complaint about the mass ordering of voting ballots in care homes, for family members, and party officials.
Electoral authorities say laws on elderly people voting in care homes are "water tight". According to the rules, the voting card must be delivered to the bedside of the person and not filled in by an assistant for them.
If the person cannot fill out the ballot themselves, they can apply for a ‘trusted person' to do it for them, although the Electoral Commission must give permission first.