The whistle-blower website while denying in a series of tweets that it had called Modi "incorruptible" also tweeted details of a number of observations made by the US Embassy on Modi's leadership style in a secret cable in 2006.
The comments attributed to Assange were in fact made by Gujarat Congress leader Manoharsinh Jadeja who told a visiting US Embassy official that the Gujarat Chief Minister is "extremely popular" because he is viewed as someone who is completely "incorruptible" and can deliver the goods, it said.
"No WikiLeaks document say #Modi is 'incorruptable', rather he is popular because 'viewed' as 'incorruptable'," the whistle-blower website said. "The Narenda #Modi "incorruptable" quote comes from Rajkot Congress party leader Manoharsinh Jadeja," it added.
The website identified Priti Gandhi, Co-Convener of Maharashtra BJP Communication Cell, as the one pushing the "fake endorsement" which was latched on to by Modi's online supporters as a high-profile acknowledgement of the BJP Prime Ministerial candidate's credentials.
Its clarification came against the backdrop of some BJP supporters circulating posters in Ahmedabad quoting Assange saying that "America is scared of Modi because he is incorruptible."
BJP, however, downplayed the WikiLeaks tweets. "We don't need a certificate from WikiLeaks or Assange on Modiji," BJP leader Mukhtar Abbas Naqvi had said. WikiLeaks also went on to tweet other secret cables sent by the US Embassy in 2006 which have criticised Modi's style of functioning.
"Views remain divided on whether Modi's leadership style will help or harm him if he enters national politics. In public, Modi can be charming and likable. By all accounts, however, he is an insular, distrustful person... He reigns more by fear and intimidation than by inclusiveness and consensus, and is rude, condescending and often derogatory to even high level party officials.
He hoards power..." one such diplomatic cable under a sub-heading "Modi's Leadership Style" said. The US Embassy, though, added that all of its interlocutors acknowledged that Modi is a modest man "who, unlike many elected officials in India, has not used his position to enrich himself or his family".
"Most contacts also say that he has purged the state administration of petty corruption at the mid and lower levels of the bureaucracy. However, several people tell us that big ticket corruption is still common," it added.
The controversy dates back to 2006, when Mumbai-based US Consul General Michael S Owen, according to WikiLeaks, met Modi.
WikiLeaks tweeted the secret cable on the minutes of the meeting in which it was also stated that the US Embassy in Delhi had cleared the document.