The Maria Sharapova story shows once again how dope cheats are treated differently by different sports.

Almost as soon as she had demurely left the podium at the end of her stage managed announcement, leading lights of her sport were saying how sorry they were for her, how it must surely have been a mistake, she's not a barefaced cheat, etc etc.

Contrast that with the treatment meted out to athlete Paula Radcliffe, who has never failed a drugs test, but was deemed to be a doper simply because of a senior MP's remarks, and cyclist Chris Froome, who has again never failed a drugs test, but is accused of cheating simply because he wins.

Tennis is of course the sport where an umpire officiated at one of its blue riband events, the US Open, while banned from the sport for corruption.

It portrays itself as a sport played by ladies and gentlemen. Ladies and gentlemen, by definition, do not cheat. Delicate matters such as crooked umpires working for gamblers and players throwing matches, are dealt with discreetly with the minimum possible publicity, preferably with none at all.

Sharapova knows this. When you are trying to protect a reputed yearly income of $30 million, you use every weapon you have. You show that you are still a lady despite this unfortunate matter, you ransack the back of the wardrobe for the nearest outfit you have to sackcloth and you play the "blonde moment" card.

You rely on your sport to close ranks around you so that the matter can dealt with quietly and expect to be rewarded for not kicking up a fuss with a light punishment.

But look at these uncomfortable facts. According to Sharapova she has been taking Meldonium for a decade on the advice of her family doctor. She has lived for most of that time in the USA - where meldonium is not authorised for medical use and cannot be bought legally. It is designed to deal with heart problems of the type that would rule the sufferer out of most sports including tennis. Its addition to the list of drugs banned in sports was well publicised six months ago, including by the Russian authorities to all Russian sportsmen and women. Why was she taking meldonium?

For me, there is only one answer to that. She has not made a mistake. She knew what she was doing. In another occupation, she would be called a big-time fraudster, making tens of millions out of a con. She should be treated like any other doping cheat, even if it means we will never again see her on a professional tennis court.

As she does not win every match she competes in, her doping raises the question - who else in her sport is doping? The only way to find out is for tennis to mount an no-holds-barred all-out search for the cheats. But the sport where competitors compete for titles in ladies' singles and gentlemen's singles won't do that. It's terrified of the publicity that would result. So the cheats get away with it, and other more realistic sports who have had to cope with the publicity of exposing their own cheats, will continue to fume about sporting double standards.

The days when so-called "amateur" sportsmen and sportswomen were deemed to be more honourable than their openly professional colleagues have long gone, but attitudes still linger. It is time for tennis to accept that it is the same as any other major sport and therefore has participants who don't let codes of conduct get in the way of ambition and greed. It needs to find them and deal with them severely. It owes as much to those who really are ladies and gentlemen and do play by the rules.