Sports scientist Stephen Dank will be grilled by investigators after the Senate voted to bolster the coercive powers of the Australian Sports Anti-Doping Authority.
Interviews with Cronulla Sharks players - shelved last month - will also resume under the new powers, which have been described as a ''game changer'' by a source close to the Sutherland club.
ASADA will be able to demand phone records, text messages, documents and medical prescriptions of players and others, including Mr Dank, regardless of whether they are self-incriminatory.
It is understood Mr Dank, who has refused to co-operate with ASADA to this point, is at the top of the list of interview targets once the law change takes effect within a month. He did not return calls.
The ASADA Amendment Bill passed the Senate late on Monday night. It is expected to clear the lower house by Thursday.
The law will give ASADA the power to compel people through a ''disclosure notice'' to attend interviews and, importantly, force them to hand over any documentation requested, including records of communications.
Those who refuse face fines of $5100 for every day they refuse to co-operate.
The government had sought star chamber powers that would force people to answer questions even if the answers would incriminate them. Sport Minister Kate Lundy and Home Affairs Minister Jason Clare are under pressure to get results after the infamous ''blackest day in sport'' press conference that launched the investigation.
But amendments secured by the Greens will mean interviewees keep the right to silence and can take a lawyer into the interview room.
Labor senator Jacinta Collins hinted at the focus on the sports scientists that have infiltrated sport.
She told Parliament: ''Importantly, a disclosure notice can go to anyone; not just athletes or their support personnel. This recognises that people outside the jurisdiction of Australia's anti-doping regime may have information that would assist ASADA to identify and sanction those who commit anti-doping rule violations.''
Australian Olympic Committee president John Coates, who has lobbied for beefed up powers for ASADA, welcomed the Senate vote.
''With this legislation and the new powers it provides ASADA, Australia remains at the forefront of the fight against doping in sport,'' he said.
ASADA interviews with Essendon players and club officials are almost complete but interviews with Sharks players have been stalled since second-rower Wade Graham attended but refused to co-operate.
Rugby League Players Association chief executive David Garnsey said he would need to read the detail of the ASADA Amendment Bill before commenting.
In its submission to a parliamentary committee that considered the bill, the Australian Athletes Alliance, which represents professional footballers, cricketers, swimmers and netballers, argued against granting ''unreasonably wide coercive powers'' and said there should have been a greater period of public consultation.