Police in NSW are using strip searches more than ever before, and many of them could be unlawful, according to a new report.

Key points: Thirty per cent of all strip searches result in a criminal charge

Thirty per cent of all strip searches result in a criminal charge One 21-year-old woman told the ABC she had been strip searched six times by police

One 21-year-old woman told the ABC she had been strip searched six times by police A police spokesperson said all recruits were taught how to undertake a strip search

Under law, strip searches are only meant to be carried out as a last resort when circumstances are deemed serious and urgent, but experts claim searches are routinely used in non-urgent circumstances.

"In many cases police aren't turning their minds to the legal criteria for conducting a strip search," said Dr Vicki Sentas, the lead author of a new report by the University of NSW.

The research, commissioned by Redfern Legal Centre, has revealed there has been an almost 20-fold increase in the number of searches in the past 12 years.

The study found between 2014-2015, and 2017-2018, searches in the field found nothing between 62.6 and 65.6 per cent of the time.

Music festival fanatic Crystal Smithers, 21, said she had been strip searched six times at festivals.

During her worst experience, Ms Smithers said she was made to strip naked, squat and cough, all while she was on her period.

"I was made to take my clothes off completely, squat and told I'd have to take my tampon out if they believed I had something concealed inside me," she said.

The officer didn't follow through, and Ms Smithers said no drugs have ever been found on her, but the whole experience made her feel humiliated and embarrassed.

"She was a woman herself so surely she could have understood how uncomfortable that would have made me feel," Ms Smithers said.

"I don't want to have to be pulled aside and strip searched and it ruin my whole night. It would be easier to stay at home and not go."

She is now reconsidering her love of "hardstyle" festivals, which has involved attending 30 music festivals in the past three years.

Wide interpretations

Dr Sentas said laws governing strip searches in NSW were unclear and open to wide interpretations.

"It's not very clear to police what exactly the definition of a strip search is," she said.

"If [officers] don't realise what a strip search is, they don't realise it needs to be recorded as a strip search and then they won't need to follow the very serious mandatory rules to protect a person's privacy and dignity."

According to the report, asking someone to remove their clothing and to squat and cough to dislodge secret items in their body does not legally amount to a strip search.

"A strip search is not meant to be a cavity search," Dr Sentas said.

"It's only meant to be a visual search and inspection of the body without touch."

"There's no special legal provision in New South Wales authorising police to conduct the procedure known as squat and cough.

"It's still a cavity search and in New South Wales a cavity search is defined as a forensic procedure and only a court can order it."

Dr Vicki Sentas said cavity searches can only be ordered by a court. ( ABC News: David Collins )

A NSW Police spokesperson said in a statement that all recruits were taught how to undertake a strip search and further training was provided throughout their career.

"Police officers do not enjoy carrying out strip searches," the spokesperson said.

"But it is a power that has been entrusted to us and searches reveal drugs and weapons."

NSW police also said strip searches represented only 1 per cent of all searches conducted across NSW, but the searches were sometimes the only way to locate dangerous items, including weapons and drugs.

"During this season's music festivals, police found many persons had secreted trafficable quantities of illegal drugs in their underwear or internally, including an 18-year-old woman who internally concealed 394 MDMA pills," the police spokesperson said.

Data obtained by UNSW showed 30 per cent of all strip searches result in a criminal charge.

The researchers say young people aged 25 and younger are among the most likely to be strip searched.

Aboriginal and Torres Strait Islander people also account for 10 per cent of all recorded strip searches in the field.

In recent years there has been a sharp increase in the amount of young people seeking legal advice about strip searches, according to Sam Lee, head of Police Accountability at Redfern Legal Centre.

"We actually need a change in the law to direct education of police on the ground," Ms Lee said.

Ms Lee claimed safeguards like being searched in private, sealed off areas were also not being followed.

The NSW Minister for Police, David Elliott, did not respond to requests for an interview but in a statement said that strip searches are governed by a "comprehensive legislative framework" that has "key safeguards".