The DNA found on a needle in a strawberry punnet is "100 billion times" more likely to belong to Queensland farm supervisor My Ut Trinh than anybody else, prosecutors have told a Brisbane court.

Ms Trinh, 50, was arrested earlier this month after a major police investigation into how needles came to be placed in strawberries that were shipped around the country.

She had been held at the Brisbane Women's Correctional Centre, but on Thursday was granted bail by the Brisbane Magistrates Court.

She has been charged with seven counts of contaminating goods.

Prosecutor Cheryl Tesch told the court that they had a "strong case" against Ms Trinh, who worked at the Berry Licious farm at Caboolture, north of Brisbane.

Ms Tesch said the police evidence included two needles found in a plastic container in Victoria.

"The DNA found on one of those needles is 100 billion times more likely to be that of the defendant," Ms Tesch said.

Police said there were 186 reports of sewing needles being found around the country. ( Facebook: Joshua Gane )

Defence lawyer Nick Dore said the case against Ms Trinh was based on "hearsay, innuendo and rumour".

Mr Dore said the police case relied on a conversation "one or two years ago" where Ms Trinh is alleged to have told another worker: "If I hate anyone, I will put the needle in the strawberry and make them go bankrupt."

However, Mr Dore said the worker did not believe Ms Trinh was being serious.

Mr Dore said his client had no motive to commit the offence, and had complied with police during the investigation.

While he conceded her DNA was found on the needle, he said that did not prove she inserted it into the fruit.

Mr Dore said Ms Trinh posed a low risk of re-offending if she was to be released on bail. He also said the risk to her personal safety was low.

"There's no evidence of vigilante justice from the fruit-picking industry," Mr Dore said.

Ms Trinh was granted bail on the condition that she not contact workers on the strawberry farm, surrender her passport and report to police three times a week.

The case was adjourned until December 17.