A police intelligence unit says it warned organised crime gangs would attempt to infiltrate T in the Park prior to the music extravaganza.
Officers in charge of Operation Gothic, which collates music concert crime trends across Europe, feared the event at Strathallan Castle, Perthshire, was a sitting duck for organised criminals.
And the specialist unit’s prediction appears to have been borne out, after the site was reportedly swamped with drugs, linked to two deaths, and even the theft of an ATM cash machine.
Speaking prior to the start of the event, a senior said a common tactic is for criminal gangs to have people on the inside working at music festivals.
She said: “The bigger the event the more difficult it is for organisers to check the backgrounds of everyone employed on-site.
“Organised crime groups are aware of that and use it to their benefit.
“Our job as part of Operation Gothic is to liaise with the music industry and promoters to share intelligence to ensure the public is protected and aware of the potential risks.
“For example, the first day of an event is more likely to be targeted as thieves know there is more cash on-site.
“We set up Operation Gothic after recognising there was no database that collated crime trends at music events.”
The future of the festival has been thrown into doubt after the deaths of two 17-year-olds before the event even started.
They have been named as Peter MacCallum, from Lochgilphead, Argyll, and Megan Bell, from the north of England.
Another fan, David Higgins, 18, of Motherwell, was taken to hospital claiming his drink had been spiked with drugs.
Organisers of the event - which attracts 80,000 people over the weekend - told attendees: “There’s no safe way to take drugs. Don’t take the risk.”
The event’s licence is now renewed on a year-to-year basis after safety concerns were raised following the event’s relocation from Balado to Perthshire last year.
Scottish Conservative MSP Liz Smith said: “Many people - including myself - gave DF Concerts the benefit of the doubt that they could sort out the problems.
“Sadly, this year’s deaths will raise yet more questions about public safety, and rightly so.”
Police Scotland said 23 people have been arrested for various minor offences.
Superintendent Conrad Trickett said: “The police continues to work with all the agencies involved to ensure the safety of those at the event.”
Nick Moore, of the Scottish Ambulance Service, said 280 people had been treated in the hospital tent “with the vast majority of cases being minor ailments”.
He added: “As always, we stress that revellers report to staff if they feel unwell or if they are concerned about a friend.”
Despite the fears, there has been no repeat of the traffic chaos which marred last year’s event.
Transport manager Ian Martin said: “Our new trans-port management plan is working well and traffic has been flowing freely.”
Police say the beginning of the festival is a prime time for criminals to strike.