Senior NSW Liberals say Gladys Berejiklian should be "more open-minded" to pill testing as the Premier indicated she would consider the measure in NSW but only if given evidence that it saved lives.

Ms Berejiklian has remained opposed to pill testing but her position appeared to waver yesterday after another drug-related death at a Victorian music festival.

Gladys Berejiklian says pill testing gives "a false sense of security" but would consider implementing it if shown evidence that it saved lives.

"If there was a way in which we think we could ensure that lives were saved with pill testing we will consider it, but there is no evidence been provided to government on that," Ms Berejiklian said.

NSW Opposition Leader Michael Daley said this week that pill testing "should not be off the table" and former Australian Federal Police Commissioner Mick Palmer has urged NSW to consider the measure.

"How a government which presides in a jurisdiction in which a medically supervised injecting centre has operated successfully and with indisputable success in Kings Cross over 18 years, can be so vehemently opposed to trialling – or even discussing or considering – pill testing is difficult, almost impossible, to understand," Mr Palmer wrote in an opinion piece in the Herald.

But the Premier has maintained that pill testing could give people a "false sense of security".

Police outside Field Day attempt to make a man open his mouth. The Sydney Morning Herald

"Pill testing doesn’t deal with overdoses, pill testing doesn’t deal with the fact that what is safe for one person isn’t safe for another person, pill testing doesn’t deal with the fact that mixing drugs and alcohol is a lethal combination," Ms Berejiklian said.

But several of Ms Berejiklian's colleagues said their views had shifted significantly on pill testing, with one saying that it was "absolutely the right thing for the government to do".

"I am very anti hard drugs but the reality is these kids are going to take pills anyway, so let's at least help them to do it safely," one senior MP said.

"I think Gladys needs to be more open-minded because just saying 'don't take drugs' is not a message any kid is going to listen to and it isn't making any difference."

Another said: "Kids are dying so what we have been doing so far clearly isn't working. Pill testing is about helping people to get advice from professionals so I don't see the downside."

"Gladys voted for the [Kings Cross] injecting room, so her opposition to this makes no sense to me."

But one senior Liberal source said that pill testing would not be a good policy to take to the election.

"I am personally sympathetic to pill testing but I just don't think it is the right political message for a conservative government to say we would condone illegal drug taking," the source said.

"The politics of drug testing would not play out well for us and even though I am sympathetic there would be some [Liberals] who would never agree to us doing it."

One MP said they would never change their position. "We can't pretend there is safe drug use," the MP said.

The debate around pill testing as been reignited after four deaths in four months from suspected overdoses at NSW music festivals and concerts.

This week, 22-year-old Brisbane man Josh Tam died after he was taken to hospital from the Lost Paradise music festival on the Central Coast.

In Victoria, a 20-year-old died from a suspected overdose on Tuesday after a festival south-east of Melbourne.

A huge police operation was launched for the Field Day festival in Sydney's CBD on New Year's Day, an event headlined by artists including Cardi B, Flight Facilities and Amy Shark.

Detective Chief Inspector Stuart Bell, who led the operation, said six people were charged with drug supply after police seized substances such as MDMA, cannabis and ketamine at the festival.

A further 144 people were charged with drug possession after a drug dog operation, while four people were taken to hospital for "drug-related health issues". An estimated 28,000 people attended the festival.

Chief Inspector Bell said police have not analysed the chemical make-up of the drugs seized.

"Obviously if you consume a drug, you don't know what's in it. You could die," he said.

"From our perspective, we encourage people not to take drugs. The question of pill testing is for the government."

New Zealand's police minister Stuart Nash said yesterday he wanted to see all New Zealand music festivals with drug testing kits by next summer.