The AFP's claim it busted a haul of more than $1 billion worth of the drug "ice" has been criticised as being massively inflated by up to four times higher than previous busts.
Officers have admitted they used an "upper range" estimate when they announced Monday they had arrested four Hong Kong and Chinese nationals for the alleged importation of 720 litres of liquid methamphetamine in bras and craft items.
But the claim the drugs were valued at $1.26 billion immediately came under scrutiny when compared to similar seizures made as recently as last month, which show it has been inflated by four times as much.
Federal police said the 720 litres of methylamphetamine could have been used to produce 504 kilograms of ice, estimating the street value to be $1.26 billion, or $2.5 million a kilo.
Yet in January the AFP announced a raid and seizure of the 159 kilos of ice at an estimated value of $106.5 million, or $666,000 a kilo.
AFP's NSW Commander Chris Sheehan told the ABC the value has been based on a range of different data, including the Australian Crime Commission's Illicit Drug Data Report and the potential street value if the total half tonne was broken down into street weights of 0.1 grams deals called "points".
"The first point I'd make is that, regardless of the value, once we have seized the drugs, they are essentially valueless because they will never ever, ever, realise a profit for organised crime," Commander Sheehan said.
"In terms of the computation of values, there are a number of different ways they can be calculated.
"The particular value of this shipment has been calculated on the basis of its value sold at a street level, which at that level — a kilogram of crystal methylamphetamine — could be broken into 0.1 gram deals, or 'points', and sold at that value.
"Now, calculating out from there brings us to the $1.26 billion."
The AFP later admitted in a statement it recently changed its methodology to "standardise calculations" and "use a single point of reference".
Criminologist and former police officer Dr Terry Goldsworthy said it was already known police tended to go for the higher range of a drug's price, but there needed to be consistency in the methodology.
"It's no secret, the ACC puts out data on prices of drugs and street prices. I'd like to see the AFP, or whoever makes that determination, put forward how they actually calculated that," he said.
The three men and one woman charged with the importation of methylamphetamine hidden in push-up bras, paint-by-numbers kits and glue remain in police custody and face life in prison if convicted.
News break – February 16