A TRIAL is currently under way at the Warwick District Court for a man charged with 12 child sex offences.

The 51-year-old Lockyer Valley man pleaded not guilty to all charges during the first day of proceedings yesterday.

Crown Prosecutor Christopher Cook told the court the alleged victim, who was just seven years old when the alleged exploitation began, was related to the man through marriage.

Mr Cook said it was claimed the first incident occurred on Christmas Eve 2012 and was followed by an ongoing unlawful sexual relationship between June 2014 and July 2015.

He said it was during this period of 12 to 14 months that 10 of the alleged offences took place.

"A few months passed in between some of the counts,” Mr Cook said.

"Sometimes it was a month, sometimes it was multiple months, sometimes it was just a week or two.”

The jury then heard the details of each charge, which included allegations of rape and indecent treatment of a child under 12 years, and the circumstances in which they took place.

Mr Cook said in some cases the offences took place in the alleged victim's home, whilst the others allegedly happened at the man's own residence.

During his opening statement, Mr Cook explained seven witnesses were expected be brought forward to provide evidence for the prosecution's case.

These witnesses included the alleged victim's parents, the defendant's wife and a doctor.

The jury will be taken on a site visit today to observe the two houses allegedly involved in the case.

The prosecution predicted the jury will be released for deliberation on Wednesday.