Amanda Tatam is on trial in Napier District Court for offending alleged to have occurred when she was a student social worker on a short-term student placement with CYF.

A trainee Oranga Tamariki social worker accused of sexually violating a 14-year-old boy in her care says he raped her.

Hastings woman Amanda Tatam, 30, is on trial in Napier District Court facing five charges of sexual conduct with a boy aged under 16, threatening to cause grievous bodily harm to the boy and his father, and a representative charge of supplying cannabis.

The alleged offending occurred between July, 2015 and February, 2017. She also faces charges of assaulting a police officer and resisting arrest when she was arrested in October last year.

STUFF Tatam is on trial in Napier District Court before Judge Tony Adeane.

Tatam was a student social worker on a short-term student placement with Child Youth and Family, now known as Oranga Tamariki.

Crown prosecutor Steve Manning told jurors on Monday the focus of the trial would be the relationship between Tatam and the boy, which involved her asking him to source cannabis for her.

Manning said Tatam would give him cannabis to smoke.

Manning said the boy had a difficult upbringing and had been in trouble with the law, and that is how he came to be in the care of social workers.

He said Tatam was 28 at the time of the alleged offending and had been a trainee social worker when she met the teen in mid-2015. They became friends on Facebook and communicated via Facebook messenger.

In mid-2016 Tatam took a four month placement with Oranga Tamariki in which she stepped in to become the teen's social worker.

Matters progressed until November 9, 2016, when she was allegedly drunk and invited the teen to her home and had sexual connection with him.

Manning said after the sexual connection, which was consensual, Tatam's demeanour "completely changed". She got angry and aggressive and told him to leave.

"He was offended and scared and couldn't understand why she had suddenly changed," Manning said.

Two days later the teen burgled Tatam's house because he was angry. Police caught him and in February, 2017 he attended a Family Group Conference with Tatam.

Months later the boy revealed what had occurred to another social worker and Tatam was arrested last October. She allegedly resisted arrest and assaulted the detective who arrested her.

She did not talk to police other than to say "all I'm going to say is he raped me".

In a police interview DVD played to the court the boy said he had purchased cannabis for Tatam 26 or 27 times, buying three to four "tinnies" on each occasion.

In cross examination of the boy Tatam's lawyer Eric Forster put it to him that he forced himself into her house, forced her to the ground, pinned her down and raped her. The teen said that didn't happen.

In a brief opening statement Forster told jurors Tatam may have smoked cannabis but "she has never, ever smoked cannabis with [the teen], she's never supplied him, he's never supplied her".

He said Tatam would tell the jury the teen had pushed her to the floor of her home and raped her.

"So, yes there has been sex, but it was not of her desire or making. She was a victim," Forster said.

He said people "of all denominations" chose not to go to police when they are victimised, and the jury would hear her explanation for this.

The trial, before Judge Tony Adeane, is expected to run for three days.