As I understand, there is a request from the public prosecutor of a Swedish city/district for him to brought before the prosecutor for interrogation. This prosecutor is a government official, prosecuting suspected criminals in name of the state. If by 'a lawyer' you mean someone who works as legal counsel for a private party, then no, they are not the same. What I meant was that a 'subpoena' (to use the in this context more or less equivalent concept in common law system) from a public prosecutor in many Western European countries is usually granted, and as such the headline is not as premature as it may seem.

Anyway, if the confusion is over the word detain then yes I agree that that may not be quite what is happening; I hadn't looked at it that way. It's not like they're going to throw him in jail (for a longer time than it takes to arrange the interrogation), it's just that they want him to be picked up by the police to be interrogated in order to determine the merits of the case.