According to Poveda, this decision was taken on 1 May by a court in the Ecuadorian capital of Quito.
"We will protest this decision… We will appeal against it tomorrow morning [Monday] both in court and in the prosecutor's office, and we will wait for the decision of these instances", Poveda said.
The lawyer recalled that Assange remains an Ecuadorian citizen, and since no investigation is being conducted against him in this country, the material evidence related to him cannot be transferred to a third country.
Poveda also noted that the UK authorities were delaying the issuance of a visa, making it impossible for him to be present at the investigation site in London.
"All these obstacles make the whole situation invalid in terms of judicial procedures", he stressed.
The WikiLeaks founder was arrested in the UK capital on 11 April after Ecuador revoked his asylum status. He was then sentenced to 50 weeks in jail for jumping bail back in 2012 when he took refuge inside the Ecuadorian Embassy in London to avoid extradition to Sweden over a sexual assault investigation that has since been dropped.
The United States, who is seeking Assange's extradition on charges of conspiracy to commit computer intrusion, has until 12 June to provide London with all the necessary documents on the issue.
Assange's lawyers and supporters fear that he could be charged under the Espionage Act in the United States and face the death penalty.