SYDNEY, May 9 (Reuters) - Meta's oversight board upheld

a decision to remove two Facebook posts calling for Australians

to vote multiple times in an indigenous rights referendum, but

noted the social media giant had not adequately explained its

ban on encouraging voter fraud.

The board, which is funded by Meta but run

independently, said Meta was correct to protect the democratic

process by preventing voter fraud when it proactively pulled the

posts ahead of the 2023 vote.

But Meta's public-facing rules were not clear enough, the

board said in a ruling published on Thursday.

"Since it is crucial that users can engage on social

media to discuss public-interest issues about democratic events,

Meta needs to clearly inform users of the rules," it said.

The decision comes as Australia's government plans to

introduce penalties for internet platforms which fail to rein in

misinformation and disinformation. Last October, Australians

voted down a proposal to constitutionally recognise Aboriginal

and Torres Strait Island people amid fears that a misinformation

campaign was influencing voters.

In the posts under review, two Facebook users separately

uploaded screenshots showing partial statements posted by the

Australian Electoral Commission (AEC) on X (formerly Twitter).

The screenshots showed the words "if someone votes at two

different polling places within their electorate, and places

their formal vote in the ballot box at each polling place, their

vote is counted". The posts failed to mention that voting

multiple times is an offence in Australia.

One Facebook user shared the screenshot with the caption

"vote early, vote often, and vote NO", while the other user

posted the screenshot with the comment: "so you can vote

multiple times ... they are setting us up for a 'rigging' ...

smash the voting centres ... it's a No, No, No, No, No".

In both cases, Meta proactively identified the posts, which

were automatically sent for human review before being removed,

but the users appealed the decision, the oversight board said.

The board said in its ruling that in both cases users were

engaged in political debate but they could not call for others

to engage in illegal behaviour that impacted the rights of

others, particularly the right to vote.

"While the calls to 'vote no' are protected political

speech, the phrases 'vote often' and 'smash the voting centres'

are a different matter," it added.