Voting envelopes distributed for Australia's landmark gay marriage poll are being returned with razors and lumps of dirt inside.
The Australian Bureau of Statistics (ABS), which is conducting the same-sex marriage survey, has now confirmed that it received these items, according to News.com.au.
However, so far only 0.3% of forms handed to authorities are spoiled or blank.
The ABS has also had to hand 14 issues to the police, however these are not in relation to items sent back in the envelopes.
Jonathan Palmer, from the ABS, told a senate committee the police referrals pertain to papers being stolen and sold online.
But the Australian Federal Police has said it will not be taking these matters any further or commenting on the reports.
More than 30 other complaints have also been made about fraud in relation to the same-sex marriage survey.
So far around 11.9 million people have taken part, which equates to around 75% of eligible voters. Those who have not yet participated have until November 7 to do so.
The results of the survey are expected to be announced on November 15.
It is not yet clear which way the vote is going to go, as although polls show the "yes" vote is roughly at 60%, its lead has been decreasing. It is thought this is due to some people who would have voted yes being complacent and not participating.