(CNN) -- A leading spokesman for WikiLeaks has said he is stepping down, citing organizational shortcomings and clashes with the group's founder.

Daniel Domscheit-Berg, who was known as Daniel Schmitt while acting as spokesman, said the whistle-blower website has structural problems stemming from its rapid growth, the German magazine Der Spiegel reported Monday.

WikiLeaks was thrust into the international spotlight earlier this year when it released some 76,000 pages of U.S. documents related to the war in Afghanistan.

"Because of the high pressure we have all been under following the publication of the American military documents, we have not been able to restructure our organization accordingly. This has created a situation in which not all of the work is being done correctly, and that is overwhelming the project," Domscheit-Berg said, according to Der Spiegel.

"WikiLeaks has a structural problem. I no longer want to take responsibility for it, and that's why I am leaving the project," he said.

Domscheit-Berg is one of a handful of people to have spoken on behalf of WikiLeaks, as the task typically falls to the website's founder, Julian Assange.

Domscheit-Berg told Der Spiegel he had clashed with Assange over what he saw as the founder's increasing concentration of resources on fewer and larger leaks, and over whether Assange should take a more back-seat role following the rape and molestation allegations made against him in Sweden last month.

"In my opinion it would have been best if he (Assange) had pulled back a bit so that he could quietly deal with these problems. It would have been fine if he had continued his normal work out of the spotlight. But he clearly saw my internal proposal as an attack on his role," Der Spiegel reported Domscheit-Berg said.

According to the account, and a posting on Wikileaks' Twitter page, Domscheit-Berg was suspended from the organization about a month ago.

"Julian Assange reacted to any criticism with the allegation that I was disobedient to him and disloyal to the project. Four weeks ago, he suspended me -- acting as the prosecutor, judge and hangman in one person," Domscheit-Berg told Der Spiegel.

WikiLeaks has previously said it plans to publish another 15,000 documents related to the war in Afghanistan soon, while Domscheit-Berg told the German magazine the group has additional leaks in the works.

"Through our rising recognition in the last six months, we have again received a lot of material that urgently needs to be processed and published," he said.