Assange spent almost seven years in the nation’s London embassy where he sought asylum, until he was dragged out by police in dramatic scenes on Thursday.
The South American nation’s interior minister, Maria Paula Romo, described staff tolerating poor behaviour from the 47-year-old, including him “putting faeces on the walls”.
But his lawyer, Jennifer Robinson, disputed the allegations when she appeared on Sky’s Sophy Ridge On Sunday.
“I think the first thing to say is Ecuador has been making some pretty outrageous allegations over the past few days to justify what was an unlawful and extraordinary act in allowing British police to come inside an embassy,” she said.
Pressed over the veracity of the allegations, Ms Robinson said: “That’s not true.”
She also said Assange’s fears of a US extradition threat were proved correct this week after allegations were made that he conspired to hack into a classified Pentagon computer.
“The politics of the case with respect with Ecuador’s change of government with Lenin Moreno coming to power and ever since then inside the embassy it’s become more and more difficult to the point where Human Rights Watch said was akin to solitary confinement,” she said.
“So he’s had a very difficult time - it’s not been easy. And to suggest that someone would chose to remain in there without legitimate concerns about US extradition, which is exactly what was proven this week, I think people can’t really understand what it would be like to live in a room like that for a very long time.”
Assange faces up to 12 months in prison after being found guilty of breaching his bail conditions when he entered the Ecuadorian embassy in 2012.
He made the move after losing his battle against extradition to Sweden where he faced allegations including rape.
Assange is now expected to fight extradition to the US over an allegation that he conspired with former army intelligence analyst Chelsea Manning to break into a classified government computer. Assange’s father John Shipton, from Melbourne, has called on the Australian government to help his son and suggested he could be brought back to his home country.
Labour leader Jeremy Corbyn has joined Assange’s supporters in saying he should be protected against extradition to the US because he exposed evidence of “atrocities” in Iraq and Afghanistan.