A trainee teacher has been arrested for allegedly grooming a girl he thought was 12 for sex online.
Western Australia's Online Child Exploitation Squad charged the 21-year old from Yanchep, north of Perth, after he was nabbed following a covert three-month operation.
Police will allege between June 12 and 17 the man used online social chat facilities to sexually engage with a police officer posing as a 12 year-old girl.
He is said to have groomed the girl by exposing her to indecent material, and eventually instructed her about sexual matters.
He was studying at TAFE to become a teacher's assistant and a few days prior to his arrest had started his practical assessment at a high school in the northern Perth suburbs.
Police are investigating if the man has been communicating or committing offences with any real children.
The man has been charged with using electronic communication with the intent to expose a child to indecent material, and one count of using electronic communication with the intent to procure a child to engage in sexual activity.
He will appear in the Joondalup Magistrates Court on July 3.