Luis Suárez has been banned for four months for biting Italy's Giorgio Chiellini but does the Uruguayan FA have a case that the photographs of the incident were altered in Photoshop?

It was the back page image across countless newspapers around the world: an outraged Giorgio Chiellini pulling down his Italy jersey to reveal a series of apparent indentations on his left shoulder. The photograph, snapped by Tony Gentile of Reuters, showed no blood. But it was evidence, it seemed, that Luis Suárez had indeed bitten Chiellini during the World Cup match between Uruguay and Italy.

I'll be honest, we all published it with a degree of relish. Not because we especially wanted Suárez to get his comeuppance – and boy has he just got it – but because we knew it was a photo that everyone would talk about.

The response on Twitter was predictably splenetic. Suárez's supporters claimed the images were manipulated, their argument promoted by a rather well-done diptych which did the rounds. The left-hand image – which had been photoshopped to remove the marks – purported to be the "real" unaltered version, while the right hand side – Gentile's original image – was labelled the fake. Trying to argue against it on social media was a futile game. Believe me, I tried. It didn't seem to matter that I could cite several other images by other photographers that corroborated the mark.

Real or Photoshop? The image that went viral on Twitter (the real version is actually on the right hand side). Photograph: Twitter

But what I and my colleagues on the picture desk found altogether more shocking was the suggestion that the Uruguayan FA might jump on the bandwagon. According to newspaper reports in Uruguay and Spain, when submitting its evidence in defence of Suárez, who has now been banned by Fifa from football for four months and nine international matches for his actions, the Uruguayan FA planned to argue that digital manipulation of images has been rife and that they cannot be trusted. Bizarre, right? Not exactly.

A quick trawl through recently published images of the incident is disturbing: for some papers, the pictures simply weren't good enough. The Mirror, for example, clearly felt it necessary to "colour correct" their close-up image so as to ensure the mark was visible. In fact, by the time the Mirror had finished with it, it was more than just visible, it was a joke. Chiellini's shoulder was a shade of red that suggested he'd been given a hickie, not a bite.

The Mirror's back page (above), which included the photo of Chiellini by Tony Gentile of Reuters and a close-up photo by Julian Finney of Getty Images.

The close-up photo. Photograph: Mirror

Facebook Twitter Pinterest The original Chiellini photo by Julian Finney. Photograph: Julian Finney/Getty Images

The thing with colour correction is that it is a perfectly acceptable form of manipulation when done to ensure correct white balance or to ensure suitable reproduction of digital colour quality in print. But the Mirror, either through intention or incompetence, went several steps too far – and removed traces of the original marks. A simple soft or hard proof would have revealed as much, but one suspects they knew this already. Let's not forget that the Mirror were one of two British tabloids to conveniently edit out Chris Ramsey, the Spurs coach, from a back page photo of Tim Sherwood and Emmanuel Adebayor in April.

The Mirror weren't the only ones to edit a Chiellini image. The Daily News in America also heightened the contrast of the existing marks in their photo to draw readers' attention to the area. That, perhaps, is more understandable, although I think they overdid it. Subtle alterations to photographs can be acceptable but they should be done in ways that do not impinge on the veracity of the image – a slight dodge or burn, perhaps, to correct exposure, or a minor canvas extension when creating a feature page. The critical thing when picture editing is to maintain the truth. How else do you expect your readers to trust you?

If the Uruguayan FA goes ahead with its appeal on the basis of Photoshop fakery, they'll have little joy. Whatever caused the mark on Chiellini's shoulder, there's absolutely no denying it was there.