In “Inside WikiLeaks: My Time with Julian Assange at the World’s Most Dangerous Website,” the former staffer, Daniel Domscheit-Berg, a German computer scientist who was WikiLeaks’ second-in-command before falling out with Mr. Assange last summer, writes of tensions between WikiLeaks’ core members and Mr. Assange. They disagreed, he writes, over Mr. Assange’s leadership style, his paranoia — he asserts that Mr. Assange began to travel with bodyguards in late 2010 — and the way he managed WikiLeaks’ finances.

When he and other core members left WikiLeaks, he writes, they decided to take much of its leaked material and a crucial system they had worked on that allows for the secure submission of new leaks. Mr. Domscheit-Berg wrote that they took the material from Mr. Assange because “children shouldn’t play with guns.”

Though Mr. Domscheit-Berg and the other defectors have started another leaking site, OpenLeaks, he writes that he does not intend to release the material himself, but will return it when Mr. Assange “can prove that he can store the material securely and handle it carefully and responsibly.”

The excerpts emerged in leaked pages of the book, to be released officially on Friday in Germany and on Tuesday in the United States. The leaked passages were confirmed as genuine by Chloe Johnson-Hill, a spokeswoman for the book’s publisher, Random House.

In response to the extracts, a spokesman for WikiLeaks, Kristinn Hrafnsson, released a statement to Forbes magazine that said WikiLeaks “has been taking legal action” against Mr. Domscheit-Berg. The spokesman also said that Mr. Domscheit-Berg did not hold significant roles within WikiLeaks and that his assertions were “based upon limited information or malicious falsifications.” WikiLeaks accuses him of “sabotage” in relation to the submissions system.

Mr. Hrafnsson did not immediately respond to a request for clarification, and Mr. Assange’s British lawyer, Mark Stephens, said he was “not in a position to comment.” Mr. Domscheit-Berg confirmed that he had received a legal letter, but said it did not specify any action.

Separately, Mr. Assange will appear in a London court on Friday for the close of a hearing to determine whether he will be extradited to Sweden to face accusations of sexual misconduct made by two women there.

Mr. Assange has repeatedly denied the accusations, saying they are part of “a smear campaign” directed by unidentified forces in an effort to silence him. But extracts from Mr. Domscheit-Berg’s book are likely to be damaging on that subject. He writes that Mr. Assange boasted of fathering children around the world and that he enjoyed the idea “of lots and lots of little Julians, one on every continent.”

www.nytimes.com/2011/02/11/world/europe/11wikileaks.html

Feb. 10, 2011