National newspaper picture editors have expressed surprise that images of the Lebanon conflict that were allegedly manipulated by a freelance went out on the Reuters wire this week.
They claimed changes made to the pictures were "crude" and easy to spot.
Adnan Hajj, a photographer used by Reuters for more than 10 years, was dropped on Sunday after it emerged on blogs that he had altered an image taken of a bombed Beirut building to add more smoke.
Reuters admitted on Monday that a picture of an Israeli fighter plane, also taken by Hajj, was also apparently doctored by him to increase the number of flares being dropped from one to three.
The agency has conducted its own investigation, sacked Hajj and vowed to change its procedures.
Daily Telegraph picture editor Bob Bodman told Press Gazette: "I'm suspicious about this. He's a very good photographer and we've used a lot of his images. I can't believe someone who's as professional as he is sent in an image that was so badly Photoshopped. If he was going to change that image properly, of smoke coming out of the city, he would never have left it like that."
Bodman, formerly a picture desk editor at Press Association, said an amateur would have made a better job of the alleged changes.
He added: "That bloke's career is now finished. Nobody's going to touch him. I feel sorry for him if it's just stupidity. I can't believe the Reuters desk editor has not been more on the ball. The editor should have a rocket up his backside."
The Times, The Guardian, The Daily Telegraph and PA say they only allow changes to news photos that can theoretically be made in a darkroom, such as exposure correction, dust removal and cropping.
Times picture editor Paul Sanders said the sort of manipulation displayed by Hajj would lead to immediate dismissal without warning from his paper.
"Many photographers use the cloning tool to drop out dust because they appear as black dots on pictures which are quite unsightly," he said.
"But there's a great difference between using a cloning tool to take dust out and using it to enhance an image. It's so badly done there's hardly any of the original smoke left and all he's done is trash what was a very usable news image into something that's not."
The Guardian's deputy picture editor, Helen Healy, said her paper would never alter a news image and would tell readers if an image in another part of the paper had been changed. She added: "In the case of the Reuters picture, it was crudely done. If I'd seen that, I'd have been immediately suspicious. Our readers quite often write letters to ask if pictures have been manipulated."
Asked why she thought Hajj had doctored the photographs, she said: "It's a very pressurised environment in the Middle East. It's arguably over-reported as a conflict, unlike Afghanistan or even Iraq, where it's almost impossible to work.
"There are probably loads of photographers operating in the region. Lebanon is a tiny area to cover. I imagine the chap was desperate for work.
"He probably felt he had to make his picture as effective as possible. He took a fantastic picture of a man on a stretcher that we used on Saturday. I don't know what happens when the conflict is over. Maybe he'll get quietly picked up again."
PA head of pictures Martin Keene said: "I think that the physical manipulation of a photograph now is something of a rarity which everybody is very vigilant in looking out for. If, at any stage, we think there's any doubt about a picture we will always go back to the original source and say, ‘Can you explain this?'"
The chairman of the Chartered Institute of Journalists' photography division, Paul Stewart, warned that the growth of citizen journalism makes picture manipulation more likely.
"There's been a number of situations where people have come up with photos that haven't actually been real. I think it was Sky that ran what was supposed to be a oil refinery fire in England which turned out to have an elk in the picture, and it actually turned out to be a two-year-old fire in Canada.
"With the flood of material that comes in now from people who aren't necessarily ‘proper' journalists, you're not 100 per cent sure of the source, which makes the job of a picture editor a lot harder."
Hajj has denied altering the pictures.
Reuters global picture editor Tom Szlukovenyi said: "There is no graver breach of Reuters standards for our photographers than the deliberate manipulation of an image.
"Reuters has zero tolerance for any doctoring of pictures and constantly reminds its photographers, both staff and freelance, of this strict and unalterable policy.
"Manipulating photographs in this way is entirely unacceptable and contrary to all the principles consistently held by Reuters throughout its long and distinguished history. It undermines not only our reputation, but also the good name of all our photographers.
"This doesn't mean that every one of [Hajj's] 920 photographs in our database was altered.
We know that not to be the case from the majority of images we have looked at so far, but we need to act swiftly and in a precautionary manner."
Reuters said that the two altered images were among 43 that Hajj had filed directly to the global picture desk, rather than through an editor in Beirut.
It said that filing drills have been tightened in Lebanon and that only senior staff on the global picture desk will now edit pictures from the Middle East, with the final check undertaken by the editor in charge.