Government backbencher Julian Hill says his parliamentary colleagues must not give credibility to "sham" elections and instead call out leaders claiming to be democratically elected.
Mr Hill criticised Cambodian prime minister Hun Sen for shutting down one of his nation's last free media outlets, Voice of Democracy radio, for allegedly slandering his son in a story.
The story said Lieutenant General Hun Manet signed a donation on his father's behalf of $100,000 for Turkey earthquake relief.
Hun Sen said the article misinterpreted the facts and that only the prime minister has the authority to make decisions on foreign aid.
His son heads the army and has been nominated by Hun Sen's Cambodian People's Party to succeed him when he steps down.
In a statement to parliament on Tuesday, Mr Hill called the Cambodian prime minister a dictator who was "up to his old tricks" ahead of an election scheduled for July.
Hun Sen has been prime minister since 1985 and is seeking another five-year term.
"How can Cambodia even pretend to be a democracy when their prime minister shuts down a media outlet in just 24 hours? It's ridiculous and embarrassing," Mr Hill said.
"This isn't about inaccurate media reporting. It's about shutting down criticism or opposition before July's elections."
Mr Hill said the Cambodian elections would not be free or fair.
"Australia must be careful not to lend credibility to sham elections," he said.
Last November, Prime Minister Anthony Albanese met Hun Sen at the ASEAN summit hosted by Cambodia.
The pair had a bilateral meeting and marked the 70th anniversary of the Australia-Cambodia diplomatic relationship.
with Associated Press