Nearly 200 people were arrested for drug offences at Sydney's Field Day music festival on New Year's Day, as the debate over pill-testing continues to rage following recent overdoses.

New South Wales Police said in a statement that 194 people were arrested during the "high-visibility policing operation" at the annual music festival in Sydney's Domain. Of those arrests, 155 involved sniffer dogs.

Around 28,000 patrons attended this year.

Six of the arrests were on charges relating to drug supply, with three of those arrested carrying 120 MDMA, or ecstacy, pills among them.

"Ecstasy [or] MDMA, ketamine, cannabis - a variety of drugs were seized yesterday," Detective Chief Inspector Stuart Bell told reporters on Wednesday.

"Ultimately young persons have to be mindful that taking drugs are not safe and illegal substances can be harmful to your health. From our perspective, we just want to encourage people not to take drugs," he said.

NSW Police issued a warning about taking drugs into the festival the day before the event.

Skip Twitter Tweet FireFox NVDA users - To access the following content, press 'M' to enter the iFrame.

"The possession or supply of prohibited drugs is a serious criminal offence. Those thinking of bringing substances into the event are reminded there will be uniformed and plain-clothed police patrolling the festival, which will include the use of drug-detection dogs," Detective Chief Inspector Stuart Bell said on Monday.

Four people were also taken to hospital for drug-related health issues.

Earlier in the week, attendees of the Falls Festival were warned of a bad batch of pills.

The orange tablet was identified as potentially lethal by medical tents at the three separate festival sites across the country.

“Regardless of pill variation, we want to remind everyone of the potentially fatal risks that come with illicit substances,” the text said.

“You do not know what is in them, how your body will react, there is no safe level of consumption. One pill can kill.”

Two fatalities in less than a week

The arrests come just days after two suspected overdose deaths at music festivals across the country.

A 20-year old man died on Tuesday after taking drugs at Victoria's Beyond the Valley Festival, and on Saturday a 22-year old Joshua Tam died after taking illicit substances at Lost Paradise in NSW.

Police are preparing a report for the coroner into the death of the 20-year old man, though they said his death is not being treated as suspicious.

Six people were arrested for drug trafficking during the Beyond the Valley festival, which ended on Tuesday, and a further 26 people were given cautions or drug diversion notices, Victoria Police said.

Sniffer dogs were also used at the Victorian festival.

Naomi Noffs from the Noffs Foundation said the drug deaths were heartbreaking but avoidable.

Skip Twitter Tweet FireFox NVDA users - To access the following content, press 'M' to enter the iFrame.

"My heart breaks for the mother and father for whom the happiest time of the year has just become the worst moment in their lives."

"Pill-testing will reduce the harm at festivals without a doubt. It's time to listen to the evidence - there's two decades of it pouring out of Europe," she said in a statement to supporters of the Take Control campaign. "Now is the time to push for safer, saner drug laws."

Former Commissioner of the Australian Federal Police, Mick Palmer, is also on board with the Take Control campaign.

"When are we going to learn that threats and our current 'Just Say No' campaign are not working?"

"Young people can get drugs easily, but don't know what they are taking. In responding to tragedy we must sometimes face hard truths. Decades of a punitive approach where we arrest young people has not worked. It is time to take practical steps to make parties safer for our kids," he said in a statement.

"Pill testing is not a silver bullet but it's a proven and positive way to help prevent this kind of tragedy, has majority support from Australians and must be at least trialled on a pilot basis - if it doesn't work then stop it," Mr Palmer said.

Is there a political appetite for pill-testing?

In May last year, Victorian Premier Dan Andrews told Hack that pill-testing was off the table entirely in Victoria, and the state government has not shifted since the recent overdose at Beyond the Valley.

A spokesperson for the state government told the ABC on Wednesday that the Andrews Government has received advice from Victoria Police that testing can give people a false and potentially fatal sense of security about illegal drugs.

NSW Premier Gladys Berejiklian again ruled out pill-testing earlier this week, despite NSW Labor shifting its position to consider the process.

NSW Opposition Leader Michael Daley said Labor would look at pill-testing if it won March's state election.

"Labor will convene a drug summit... if you're going to hold a drug summit and you're going to listen to the experts, you can't shut one door to them," Mr Daley said.

Pill-testing should not be off the table... You have to keep an open mind to what the experts might throw up.

The Palaszczuk Government in Queensland has cautiously opened the door to pill-testing, with Health Minister Steven Miles saying the Government would study the findings from Australia's first ever trial at Canberra's Groovin the Moo festival last year.

"Queensland Health is considering the findings of that report (from Canberra)," he said in a statement to the Courier Mail.

Triple j's massive What's Up in Your World survey found that more than four out of five of our listeners - 83 per cent - were in favour of pill-testing at music festivals, and 55 per cent had attempted to take drugs into festivals in the past.