BEIJING (Reuters) - A Chinese photographer has apologized for his "bad behavior" forging an award-winning picture of pigeons, Xinhua news agency said on Monday.

Zhang Liang, a former photographer for the Harbin Daily newspaper, admitted that he added a pigeon to a photo, using Photoshop software, which showed pigeons receiving bird flu vaccine shots from medical workers.

The photo won the top prize in the first China International Press Photo Contest, held by the Photojournalist Society of China in 2005.

"I would like to apologize to the public," Zhang, who was dismissed from Harbin Daily four days ago, was quoted as saying.

He copied the pigeon in the top right corner of his photo and pasted it in the top left corner.

"I did it to make the photo perfect," Zhang was quoted as saying. "It was the first time for me to perfect pictures with computer technology and I did it only once."

In February this year, an award-winning photographer, Liu Weiqiang, admitted he faked a photo showing more than 20 Tibetan antelopes roaming peacefully under a railway bridge along the Qinghai-Tibet railway where a train was roaring past.

His photo had been chosen as one of "the 10 most impressive news photos of 2006," an annual event sponsored by Chinese Central Television.

Last year, a row broke out over a photograph of a tiger purportedly snapped in the wild and believed to be fake.

(Reporting by Nick Macfie; Editing by Valerie Lee)