"Two civil servants told him how the Swedish judicial system works and how the European arrest warrant system works," Anna Erhardt, a spokeswoman for Justice Minister Beatrice Ask, told AFP.
She said the ambassador had taken the initiative to Thursday's encounter, but refused to comment further on the meeting.
Assange has taken refuge in the Ecuadorian embassy in London since Tuesday when he asked Quito for political asylum in a last-ditch effort to avoid extradition to Sweden where he is wanted for alleged sex crimes.
Ecuador's President Rafael Correa has said he is considering the request, but stressed that the decision would not be rushed, and has recalled Ecuador's ambassador in London to brief him on the situation.
Assange, a former computer hacker, who is wanted by Sweden to face allegations of rape and sexual assault against two women, will remain in the embassy building until a decision is reached.
The 40-year-old Australian national fears Stockholm will turn him over to the United States, which he says wants to try him for leaking US secrets.
His whistleblowing website WikiLeaks enraged Washington by publishing a flood of classified US information about the wars in Iraq and Afghanistan, as well as more than 250,000 classified US diplomatic cables.
There is however no current US indictment against him and Australian Foreign Minister Bob Carr insisted in an interview with the Australian Broadcasting Corporation Sunday he had "received no hint that (the Americans) have got a plan to extradite him to the US."
Sweden, which has seen its judicial system come under attack during Assange's marathon legal battle to block Britain from extraditing him, has meanwhile insisted it only wants to question Assange about his alleged sex crimes.
The Swedish prosecution authority has stressed it will be bound by the so-called "principle of specialty," meaning it cannot try Assange for any crimes other than those stated in the European arrest warrant.
It also has also said it cannot legally send him to the United States without an official request from Washington, something it says it has not received, and without permission from Britain, the original surrendering country.