Lopez, arrived in the Spanish capital on Sunday after first crossing into Colombia, Spain’s Foreign Ministry confirmed.
He fled to the embassy in April last year, after being involved in an abortive incursion to kidnap President Nicolas Maduro. He was also considered to be the mentor of opposition figure Juan Guaido.
Caracas, which has formerly slammed Spain’s move in harboring “criminals,” accused Madrid of “incessant" interference in Venezuelan affairs over Lopez’s exit.
"The head of the Spanish diplomatic mission in Venezuela served as the main organizer and confessed accomplice of the... escape from Venezuelan territory of the criminal Leopoldo Lopez," the government said in a statement.
It said Spain’s behavior was “hostile, outrageous and unacceptable” and that it violated the Vienna Convention on diplomatic relations.
“The Kingdom of Spain actively participates in the illegal escape of a dangerous criminal and decides to receive him in its territory without regard to international laws and even Spanish immigration laws and bilateral agreements on justice,” the statement added.
Caracas had expelled Spanish ambassador Jesus Silva in January 2018 over allegations of interference in the country's affair, but his return was agreed in April the same year.
Now, it says that Silva has failed to live up to his commitment to respect "Venezuelan and international laws," by “facilitating” the escape of “the terrorist Leopoldo Lopez.”