Some of Australia's most respected medicine experts, who compiled a doctors' guide to children's drugs published by the world's top health body, were accused of copying dozens of passages from a pre-existing publication, The Australian reported Friday.

The World Health Organization (WHO) launched an investigation into how much material was duplicated from an earlier source in its 528-page WHO Model Formulary for Children.

In a letter sent to the WHO in Geneva, the publishers of the Australian Medicines Handbook (AMH), an independent guide for Australian doctors, said that a comparison turned up 50 instances in which "substantial passages from the WHO Formulary ... are identical to the corresponding passages in the AMH."

"It is difficult to escape the conclusion that the passages referred to were copied from the AMH, especially as we understand the content of the WHO Formulary was prepared in Australia, where the AMH is widely distributed," the letter sent in December said.

The letter also warned the WHO there might be more than 50 examples of copied passages because AMH staff had analyzed only about 60 percent of the WHO guide's pages since being alerted to the problem by an AMH editor who recognized her words in the WHO document.

In the letter, a copy of which was obtained by The Australian, AMH general manager Peter Farrell said that the examples "appear to represent a significant breach of our intellectual property rights."

Despite asking the WHO to analyze the entire document, replace any copied passages and print an acknowledgment of the issue while this was being done, AMH chairman Tony Nunan said the WHO had "not accepted that any copyright breach has occurred."

Instead, the UN health body had "undertaken to make a forensic comparison of the two publications to examine the issues we have raised," Nunan said.

The WHO guide was compiled by medicine experts from the University of Melbourne and the city's Royal Children's Hospital, who won the contract to update the Formulary in 2009.

The clinical editors of the WHO guide defended their work Thursday night, saying that there were "limited ways in which this information can be presented safely so as not to deviate from the manufacturer's instructions or warnings."

Click here to read more on this story from The Australian.