Former International Association of Athletics Federations (IAAF) President Lamine Diack is now being accused of "active", rather than "passive", corruption by French magistrates.
This means more time will be permitted for the investigation by the National Office for Financial Prosecutions before a decision is made on whether to send the case to a trial.
Diack, the Senegalese octogenerian replaced as President by Britain's Sebastian Coe in August, is accused of accepting bribes to cover up positive drugs cases involving Russian athletes.
Under French law, the tougher charge of "active" corruption generally involves offering money or other promises in exchange for violating a rule.
This comes as new preliminary charges focus on suspicions that Diack bribed Gabriel Dollé, the former director of the IAAF’s medical and anti-doping department, Associated Press has reported citing an unnamed official.
It has been a tumultuous period for Diack and the IAAF since the World Anti-Doping Agency's Independent Commission confirmed reports of sate-supported doping within Russian athletics.
An email sent by IAAF deputy secretary general Nick Davies, also chief of staff to Coe, was published yesterday by French newspaper Le Monde revealing that he considered delaying the release of Russian doping cases.
Davies has denied any wrongdoing, and claimed the email was just a "brainstorm" which was not acted upon.
Diack has also reportedly admitted to French police that he asked Russia for €1.5 million (£1.1 million/$1.6 million) to help him mount a political campaign in his native Senegal.
Le Monde also claims it has obtained transcripts of Diack's interviews with police where he admits to having spoken with former All-Russia Athletics Federation (ARAF) President and IAAF treasurer Valentin Balakhnichev in 2011 about needing money.
It has been claimed Diack wanted to finance opposition against Senegal's then-President Abdoulaye Wade, although the alleged recipient, the Alliance for the Republic party, have denied receiving payments.
The IAAF has banned Russia from international competition following the report by the Independent Commission, which is headed by Richard Pound.
He is due to release the second part of his findings on January 14.
This part is set to focus more specifically on the allegations of corruption surrounding the world governing body.