Julian Assange's former right-hand man on the Wikileaks website denounces Assange as an irresponsible, autocratic bully who once threatened to kill him in a book launched on Thursday.

In the book Inside Wikileaks: My Time with Julian Assange at the World's Most Dangerous Website, Daniel Domscheit-Berg says he quit the site in September over disagreements about WikiLeaks management and after being falsely accused by Assange of leaking WikiLeaks own internal secrets.

The book also suggests that WikiLeaks' ability to receive new leaks has been crippled after a disaffected programer unplugged a component which guaranteed anonymity to would-be leakers, a development which activists and journalists who have worked with the site confirmed to Reuters.

Neither Assange, nor members of his entourage responded to e-mailed requests from Reuters for comment on the book.

But a WikiLeaks spokesman confirmed the website's submission system was being overhauled, criticized Domscheit-Berg for allegedly exaggerating his involvement with WikiLeaks and said it was taking legal action against him for sabotage.

Domscheit-Berg, who under the pseudonym Daniel Schmitt had been one of the website's principal spokespeople, also took a backlog of leaks sent to the WikiLeaks website with him when he left, said a source familiar with the contents of the book.

Inside WikiLeaks describes the intensity of the animosities between Assange and Domscheit-Berg which led the latter to turn on his former close friend.

There were times when he threatened me very intensely, threatening either to chase and to kill me or eventually, to come with the police and have us all jailed, Domscheit-Berg told a Berlin news conference.

Domscheit-Berg said Assange never conferred with others about how to proceed and several times he released material despite internal agreements not to.

This is data that has not been edited and which may still include information on the sources, he said. This is simply irresponsible.

In a statement issued to the Forbes website on Wednesday, Kristinn Hrafnsson, a WikiLeaks spokesman, said the website was undertaking legal action against Domscheit-Berg, who with Assange served until late last year as one of WikiLeaks' two principal spokesmen.

In (his) book Domscheit-Berg confesses to various acts of sabotage against the organization...The former WikiLeaks staffer admits to having damaged the site's primary submission system and stolen material, Hrafnsson's statement said.

The sabotage and concern over motives led to an overhaul of the entire submission system, an ongoing project that is not being expedited due to its complex nature and the organizations need to focus its resources on publication and defense, Hrafnsson added.

CRIPPLED FOR MONTHS

The activists and journalists who have worked with WikiLeaks and Assange, who faces a sexual misconduct investigation in Sweden, say the website's ability to receive new leaks of data has been crippled, if not totally disabled, for months.

Domscheit-Berg recently announced that he was creating a WikiLeaks spinoff or rival called OpenLeaks.org with support from a former WikiLeaks programer, believed to be a German, whose programing skills are more dazzling than Assange's.

Precisely how much material sent in to WikiLeaks is now under the control of Domscheit-Berg and the programer, known only as The Architect, is unclear.

Domscheit-Berg has not publicly characterized the subject matter or volume of material he has stashed away, though he has indicated that at some point, he might be willing to cede control over it back to Assange.

The new website will not itself publish or analyze leaks which it receives but instead with serve as a conduit to relay the information to partners in the website, who could include media outlets, NGO groups, and labor unions.

WikiLeaks insiders say Assange still has control over substantial quantities of data leaked to the website before the he became entangled last August in the sexual misconduct case. He has said in the past this includes a huge cache of data from the hard-drive of a Bank of America executive.

In an interview with the German weekly magazine Stern, Domscheit-Berg is quoted saying that Assange's cache of bank data is old and completely unspectacular.

(Writing by Mark Hosenball and Sarah Marsh; editing by Philippa Fletcher)