A middle-aged army warrant officer who engaged in sexual activities with a 14-year-old girl was yesterday jailed for 10 months.

Teo Chye Siong, now 44, had pleaded guilty to two charges of sexual penetration of a minor.

A District Court heard that he became friends on Facebook with the teenager in May 2014.

He soon started to inject sexual content into their conversations.

Later the same month, Teo, a former regimental sergeant-major with the 6th Battalion, Singapore Infantry Regiment, met her at the void deck of her home.

He drove her to Changi Beach, where they sat on a bench facing the sea and he violated her, the court heard.

Later the same day, he drove her to Pasir Ris Park and told her to perform a sex act on him, while they sat in his car.

She complied for a few minutes.

"After Teo and the victim parted ways, Teo continued to chat with the victim on Facebook about having sex with her," said Deputy Public Prosecutor (DPP) Kavita Uthrapathy.

In calling for a stiff sentence, the DPP noted that Teo's own children were around the same age as the victim.

Teo had, moreover, known that she was a minor, but continued to send her lewd messages on Facebook about having sex with her until December 2014.

The maximum punishment for sexual penetration of a minor is 10 years' jail and a fine.

Teo has been suspended from the Singapore Armed Forces.