Matthew Paul Hockley admitted he added the teenager on Snapchat and sent her messages, but said he was interested in the girl's mother.

But after a five-day trial and nearly six hours of deliberating a jury found him guilty of one count each of grooming a child under 16 with intent to facilitate the procurement of a sexual act and using the internet to procure a child under 16.

Hockley committed the offences while he was a senior constable working at the Inala Child Protection and Investigation Unit. He has since resigned.

The 33-year-old was accused of making sexual and suggestive comments to the girl after adding her on social media days after he interviewed her over naked photographs she had circulated.

The pair exchanged more than 1000 chat messages and 30 images over three weeks from July 30, 2019.

In messages photographed by the girl he wrote, "heading home to get naked and relax" and "rather be chillin with you".

In another he said, "I was so cold last night. Needed you to warm me up".

The trial heard the former officer also invited the teenager on holiday, told her he slept naked and called her "beautiful" in some messages to her. He was also accused of commenting on sexual interactions between older men and girls.

No messages could be retrieved during the investigation because Snapchat messages - which can include photos or text - are automatically deleted after being viewed. Senders are also notified if someone takes a screenshot of conversations.

But the girl did take pictures of three conversations using another device.

Hockley claimed the photographed messages were inappropriate, "an overshare" and "a horrible use of language".

But his explanations were rejected by the Brisbane District Court jury on Tuesday.

However, the jury did find him not guilty on one count of grooming a child under 16 with intent to expose to indecent matter.

Hockley is expected to be sentenced on Friday.

His bail was extended until sentencing.

Australian Associated Press