Julian Assange has been accused of trying to create a "centre for spying" in the Ecuadorian embassy that sheltered him.
Ecuador's President Lenin Moreno, in making the accusation, says no other country had an influence over the decision to revoke the WikiLeaks founder's asylum, which the leader claimed followed repeated violations by Assange.
The comments in an interview with The Guardian show the degradation of Assange's relationship with Ecuador, which allowed him to stay in the London embassy for nearly seven years.
But the 47-year-old was dragged out by police in dramatic scenes on Thursday. He now faces jail for breaching his UK bail and possible extradition to the US.
Moreno, who became president in 2017, said his nation's previous government provided facilities within the embassy "to interfere in processes of other states".
"We cannot allow our house, the house that opened its doors, to become a centre for spying," Mr Moreno told the newspaper.
"This activity violates asylum conditions. Our decision is not arbitrary but is based on international law."
The president also made references to Assange's apparently poor hygiene following allegations made by Interior Minister Maria Paula Romo, which included Assange "putting faeces on the walls".
Assange's lawyer, Jennifer Robinson, disputed the claims 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.
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.
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.
More than 70 MPs have also urged the government to ensure Assange faces Swedish authorities if they request his extradition.
Australian Associated Press