[dagw]

no charges have been filed

That's just an artifact of the terminology used by the Swedish legal system. Charges cannot be filed in absentia in Sweden. The act of formally charging someone comes after questioning and must be done with the person present.

[spindritf]

That is true but they could've questioned him in England, or even in the Ecuadorian embassy. They have questioned people outside of Sweden in other cases. It's the prosecutors "opinion" that he needs to be present in Sweden.

[dagw]

He isn't wanted simply for questioning in the US sense of the word. He's wanted for arrest and formal charging, it just so happens that in Sweden the step that must happen before that in the standard procedure is called 'questioning'. Do the police from one country even have authority to formally charge and arrest someone on foreign soil, let alone in the embassy of third of a nation while on foreign soil? Can you link to one of these other cases where that is happened?