The 60-year-old was intercepted by Australian Border Force on Tuesday when he arrived at Sydney Airport on a flight from Cambodia.
After an intelligence-led screening, officers examined his luggage and allegedly located child abuse material on his phone.
They referred the matter to federal police, who allege they identified sexualised conversations with and about minors in addition to child abuse material.
A laptop, tablet, and USB were found in the man's luggage and seized for forensic analysis.
More devices are being examined after a search of a home in Leichhardt in inner Sydney by police and other authorities.
The man will face a bail court on Wednesday.
He has been charged with possessing or controlling child abuse material obtained using a carriage service, transmitting such material and a related import charge.
The maximum penalty for the child abuse material charges is 15 years' imprisonment.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
Lifeline 13 11 14
Kids Helpline 1800 55 1800 (for people aged 5 to 25)
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