IF YOU think it right and proper that a paedophile who blows the whistle on fellow child-abusers should receive a more lenient sentence, then you may well approve of the early release from suspension this week of Russian doping cheat Liliya Shobukhova.

I simply cannot share that view. Shobukhova won the 2010 London marathon, and also finished second and third. She won in Chicago a record thrice in a row, and total marathon winnings alone (including $500,000 for both of her World Marathon Majors series victories) plus appearance fees and time bonuses, were some $2m.

This ignores income from 10k and half marathon races, fees for track events, or sponsorship. One can gauge the scale of her income from her desire to protect it. A report in the French paper, L’Equipe, quoted her agent, Andrei Baranov, stating that Shobukhova had paid $600,000 to the All-Russia Athletics Federation to escape a ban which would have excluded her from the London Olympics.

Yet the World Anti-Doping Agency has knocked seven months from a 38-month suspension, allowing Shobukhova to return to competition with effect from last Sunday. They say she has rendered "substantial assistance" which under their code permits them to reduce sentences.

The will help them target other cheats, as well as officials and support personnel. Why should she help if there is nothing in it for her, goes WADA's logic.

Shobukhova, second fastest marathon woman ever, has agreed to co-operate with their investigation, and adjudication of cases resulting from her evidence. If she fails to comply, the original ban can be reinstated. But what reliability can one put on the evidence of a serial cheat and liar?

Russian authorities suspended Shobukhova for two years last April – given that she'd had a child in 2013, a rather meaningless sanction. The International Association of Athletics Federations felt this inadequate, and sought a four-year ban at the Court of Arbitration for Sport. Eventually 38 months was agreed.

The IAAF targeted the three-time Olympian and made their case on the basis of abnormal values in her biological passport, a tracking programme which they pioneered.

WADA decline to give further details which could be used against others implicated in her case, and might undermine their attempts to catch them.

Both the IAAF and London Marathon responses to the shortened sentence were couched diplomatically. It's fair to assume it does not fill them with joy, but it is compliant with the latest edition of the WADA code, so they are stuck with it.

The London Marathon "notes the decision" by WADA but said their "zero-tolerance policy towards doping is unaltered. Shobukhova is still banned for life from the London Marathon". Or any other World Marathon Major.

London has already begun legal proceedings against her. Their CEO, Nick Bitel, a lawyer, said: "We are determined to make marathon running a safe haven from doping. This means that cheats should not be permitted to keep their ill-gotten gains under any circumstances."

The winner of the last two Chicago and Boston marathons, Rita Jeptoo, is also at risk of forfeiting winnings after a positive test for blood-boosting erythropoietin. The IAAF wants CAS to double the two-year ban imposed by Kenyan athletics.

World record-holder Paula Radcliffe said what Shobukhova did was: "Fraud on so many levels, so much money effectively stolen in appearance fees, winnings, and endorsements."

But no big-city marathon is obliged to re-allocate prize and appearance money to those who have been cheated. That will happen only if Shobukhova returns the money, and it is doubtful whether UK courts can enforce that.

It has been reported that WADA, under Scottish chairman Sir Craig Reedie may impose a blanket ban on the likes of Russia for serial offences, but a spokesman said yesterday that Sir Craig had been taken out of context in a TV interview. WADA has no such jurisdiction. They can only declare a country non-compliant with its code, and it is for the sports movement and UNESCO to act.

However the IOC charter allows them to exclude any sport at any time, and the movement is long overdue imposing such a penalty. What countries such as Russia have done is a betrayal of sport. And the attitude to Justin Gatlin's defeat by Usain Bolt in Beijing suggests the public agree.

Professor Kristian Gundersen of Oslo University has presented compelling evidence, from mice, that even after prolonged time off steroids, the animals retain the capacity to out-perform those which have not been exposed to steroids.

WADA, he said yesterday, won't take action until there is proof from humans. "Ethically that's a problem, so we are some way from providing that evidence."

He questions the burden of proof required when people guilty of illegal drug use return and match or surpass previous results from their doping era.

"As a scientist, it's not my place to give an answer. That's a political decision, but public opinion seems to be that cheaters should not be let back in again.

"In many ways, sport is broken. People want clean sport and it seems anti-doping is not in agreement."

He accused sport of "window-dressing, rather than trying to catch cheaters". He cited cross-country skiing doing lots of tests in summer. "You can say you're making lots of tests, but not at the critical time. Making sport look good is perhaps easier than exposing fraud."

Seb Coe's promise of zero tolerance is welcome. We note Jessica Ennis-Hill is still denied the heptathlon gold she should have been awarded from two years ago when she finished runner-up to Tatyana Chernova. The Russian was caught by retroactive testing, and all results for the two years leading up to the 2011 World event were expunged. So Chernova competed in Daegu without having a legal qualifying standard.

That's for the IAAF to address – not WADA.