EXCLUSIVE: 7News has been given exclusive details of organised crime gangs importing performance enhancing substances for our elite athletes.

The six NRL clubs implicated in the drugs in sport scandal have been told the investigation could take months.

"We understand this will be a drawn out process, it won't happen over a couple of weeks," said Penrith General Manager Phil Gould.

Penrith players flew out to New Zealand for a pre-season trial today, leaving behind a scandal that threatens the integrity of rugby league.

Theirs is among six clubs implicated. The Panthers join Cronulla, Manly, Newcastle, Canberra and North Queensland.

This afternoon the six clubs were briefed by doping agency officials.

The World Anti-Doping Agency painted a grim picture, but now 7News can reveal more shocking revelations of links between organised crime and the importation of performance enhancing drugs.

"The whole inquiry in Australia commenced with Customs seizing a few hundred parcels which show there was some sort of pattern of importing drugs from Canada in fact," World Anti-Doping Agency chief David Howman said.

"The guys who are doing this are making more money than they can pushing heroin. Its as simple as that," WADA CEO David Howman said.

Federal Sports Minister Kate Lundy practiced her golf swing today, but on Thursday she'll host crisis talks with her state counterparts.

"If you've got organised crime and criminal figures in and around our elite sports people, that in itself is enough to set alarm bells ringing," New South Wales Sport Minister Graham Annesley said.

"Because that exposes them to all sorts of other influences, that we probably don’t really want to think about."

There's been widespread criticism the National Rugby League has been too slow to react, and allay the fears of the fans in the game's heartland.

It's also been a baptism of fire for new NRL chief executive, David Smith, who's been in the chair for a week and is dealing with one of the biggest scandals in the game's history.

"Due process has to be followed there has to be a fair and due process," National Rugby League CEO David Smith said.

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