World athletics president Sebastian Coe has stepped up his review aimed at cleaning up the sport's battered reputation after the latest allegations of bribery extortion and doping cover-ups left athletics facing a long road to redemption.

Briton Coe who was elected president of the sport's IAAF governing body in August on a manifesto promising reform said on Sunday that he reacted with "shock anger and sadness" when French authorities this week placed his long-serving predecessor Lamine Diack under formal investigation on suspicion of corruption and money laundering.

Senegalese Diack 82 who Coe once described as the sport's spiritual president is alleged to have received more than one million euros ($1.1 million) in bribes in 2011 to cover up positive doping tests of Russian athletes.

His son Papa Massata Diack along with three others has also been charged with various alleged breaches of the IAAF's Code of Ethics. Diack's family has dismissed what they described as excessive and insignificant accusations.

Coe told BBC Radio Five Live on Sunday: "I was in clear shock and a great deal of anger and a lot of sadness. These are dark days for our sport but I'm more determined than ever to rebuild the trust in our sport.

"It's not going to be a short journey and the day after I got elected I started a massive review and understandably in light of the allegations that were made this week that review has been accelerated.

"I'm determined to rebuild and repair the sport with my council colleagues but this is a long road to redemption."

The IAAF this year vigorously defended itself against allegations of widespread doping in the sport and that it had failed to properly investigate thousands of dubious drugs test results between 2001 and 2012. Before being elected Coe described those allegations by Britain's Sunday Times newspaper and German broadcaster ARD as a declaration of war on athletics.

Despite being an IAAF vice-president for half of Diack's 16-year reign he said on Sunday that he had no inkling of any wrongdoing until the allegations surfaced this week.

"If these allegations are proven then clearly bad people have manipulated the system and we will need a system of checks and balances to make sure bad people don't get into those positions in future" Coe said.

"In hindsight those systems should have been in place. My task now is to make sure they are and build a sport that is accounatble responsible and responsive but it's going to be a long road and we should not kid ourselves here."

Coe's comments came as one of the three co-authors of a report by the World Anti-Doping Agency (WADA) into wrongdoing within athletics - to be published on Monday - said that the sport is dealing with a "whole different level of corruption" to that which has plagued soccer's governing body FIFA.

Richard McLaren a Canadian law professor and sports lawyer told the Sunday Times: "Here you potentially have a bunch of old men who put a whole lot of extra money in their pockets - through extortion and bribes - but also caused significant changes to actual results and final standings of international athletics competitions.

"This is a whole different scale of corruption than the FIFA scandal. This report is going to be a real game-changer."

Soccer's world governing body FIFA has been in turmoil since 14 officials and sports marketing executives including two FIFA vice-presidents were indicted by the United States in May.