In a tweet, WikiLeaks said: "We can confirm Ecuador cut off Assange's internet access Saturday, 5pm GMT, shortly after publication of Clinton's Goldman Sachs speechs."
Assange has been taking refuge in the Ecuadorian embassy in London since August 2012. He has been accused of rape in Sweden and the country has said recently that it is willing to interview him in the embassy.
WikiLeaks has been releasing material about the Democrats for some time but none of it has proved to be anything close to politically explosive.
We can confirm Ecuador cut off Assange's internet access Saturday, 5pm GMT, shortly after publication of Clinton's Goldman Sachs speechs.— WikiLeaks (@wikileaks) 17 October 2016
WikiLeaks released three transcripts of paid speeches given to Goldman Sachs by Clinton, material which she has refused to release during the campaign despite being asked to do so.
The BBC said it had not been able to obtain any reaction from Ecuador's ambassador and London's Metropolitan Police had refused to comment.
Whether this will change Assange's relationship with Ecuador is not clear.