In the wake of the Houston Rockets' Dwight Howard admitted to using the banned "Stickum" spray on his hands to help with grip in an NBA match against the Atlanta Hawks, we look at five other instances where sportspeople have taken the rules to the limit and beyond.

1. Deflategate
The name given to one of the biggest and most bizarre of sports controversies in recent years centred on the footballs thrown by New England NFL quarterback Tom Brady in his team's victory over the Indianapolis Colts in the 2015 AFC Championship game. Brady denied deflating the balls to less than 12.5 PSI (the regulation limit), but the story kept going and an investigation was launched. Brady was suspended without pay for four matches by the NFL.

2. Bloodgate
A sinister one, this. The incident happened during the Heineken Cup quarter-final rugby match between Harlequins and Leinster at the Stoop in 2009. Harlequins coach Dean Richards wanted injured kicker Nick Evans, a Kiwi, back on the field as the clock ticked down on a 6-5 deficit, with wing Tom Williams needing treatment for a cut lip. The problem was Williams' lip wasn't cut - he had bitten a fake blood capsule and winked to the reserves bench on the way off (which was seen by TV viewers). The truth eventually came out and Williams was banned for four months and Harlequins fined more than $500,000. Richards resigned and was given a three-year ban.

3. Mechanical doping
Some famous (current) cyclists have been accused of this recently - but no evidence has been forthcoming. However, Femke Van den Driessche, the current Belgian and European Women's U23 Champion was only last month found to have a motor in the bottom bracket of her bike in the cyclo-cross World Championships. Coincidentally, Van den Driessche, who didn't finish the race due to mechanical problems, had "no drugs" stickers on her helmet.


4. America's Cup scandals
Too many to list here, so we'll go with one of the most recent: Oracle using a kingpost that was too long and had illegal lead weighting, which helped with the rigidity and stability of their AC45. They were not caught by measurers until the America's Cup youth regatta and were forced to vacate their ACWS title and took two penalty points into the America's Cup match against Team NZ in San Francisco. Yes, that was before they came back from an 8-0 deficit to win 9-8.

5. Aussie cricket skulduggery
More of the same here but again we'll go with the most recent - intentionally scuffing the ball in the recent test series victory over New Zealand here in order to get the ball to reverse swing. Apart from shining the ball cricketers aren't allowed to alter its appearance, but the Aussies did so by continually throwing the ball into the rough pitch when returning it from the outfield.