An Australian politician has been convicted of supplying drugs after he initially dismissed a video showing him snorting a white substance as a “deepfake”.

Former South Australian Liberal party leader David Speirs was fined A$9,000 (£4311; $5,720) and ordered to complete 37.5 hours of community service by an Adelaide court on Thursday.

Speirs was arrested in September after footage of him snorting off a plate was published by News Corp. He initially denied wrongdoing and reportedly told the news outlet it was a “deepfake” and that he had never used cocaine.

However, he later admitted that was a lie and the ensuing scandal and charges led to his resignation from parliament.

Last month, Speirs pleaded guilty to supplying cocaine to two men in August.

Speirs’ defence said he used drugs “as a form of escapism” from the stress of his work, but the offences did not occur in a work capacity.

The case had sparked intense media scrutiny, with prosecutors arguing that it was in the public’s interest given Speirs’ senior position in politics.

His lawyer had previously asked the court not to record the conviction so his client could travel overseas, but the magistrate said the offences were “too serious”.

“The need for public denunciation for this type of offending and the need for general deterrence is too great to refrain from recording a conviction,” magistrate Brian Nitschke said on Thursday.

Nitschke acknowledged Speirs’ defence that the offences occurred during a time of stress but added it was “certainly no excuse”.

Speirs stepped into the role of South Australia’s Liberal leader in 2022 and had served 10 years as a member of parliament.

He did not speak to media after his sentencing.