Two of the 11 piglets glow fluorescent green from their snouts, trotters and tongues under ultraviolet light, according to the Northeast Agricultural University in Harbin city.

Their mother was one of three pigs born with the trait in December 2006 after pig embryos were injected with fluorescent green protein.

'Continued development of this technology can be applied to...the production of special pigs for the production of human organs for transplant,' Professor Liu Zhonghua, who oversees the breeding programme, said in a news release posted on the university's website on Tuesday.

The birth of the glowing piglets proves such transgenic pigs are fertile and can pass on their engineered traits to their offspring, he said.

Dr Robin Lovell-Badge, a genetics expert at Britain's National Institute for Medical Research, said the technology 'to genetically manipulate pigs in this way would be very valuable'.

He had not seen the research from China's cloned pigs and could not comment on its credibility.

He said, however, that organs from genetically altered pigs could potentially solve some of the problems of rejected organs in transplant operations.

He said the presence of the green protein would allow genetically modified cells to be tracked if they were transplanted into a human.

The fact that the pig's offspring also appeared to have the green genes would indicate that the genetic modification had successfully penetrated every cell, Dr Lovell-Badge added.

But he said much more research and further trials - both in animals and in humans - would be necessary before the benefits of the technology could be seen.

Tokyo's Meiji University last year successfully cloned a transgenic pig that carries the genes for human diabetes.

South Korean scientists have cloned cats that glow red when exposed to ultraviolet rays - an achievement they said could help develop cures for human genetic diseases.

ASSOCIATED PRESS