A Moroccan asylum seeker arrested in Germany is not linked to the attackers who carried out bombings in the Belgium capital, broadcasters rbb and SWR reported on Saturday.

The prosecutor's office in Giessen had been analysing the mobile phone of the 28-year-old man, who was arrested on Thursday in the town north of Frankfurt when found to have non-matching identification documents after returning from Brussels.

The man had reportedly received a mobile phone message from someone called Khalid Al Bakraoui, the name of the man Belgian police say blew himself up Brussels' Maelbeek metro station on Tuesday.

Citing security sources, rbb/SWR said investigations by Belgium authorities had found that this was a mix-up and the man was instead acquainted with a person who had an almost identical name to el Bakraoui.

The man had also reportedly received a mobile phone message that included the word "fin" - French for "end" - a few minutes before the explosion at the metro station.

Security sources now assume the word was meant to signify "where" transcribed from Arabic, rbb/SWR said.

The broadcasters cited a spokeswoman for the federal prosecutor's office as saying they were in direct contact with Belgium authorities and there was so far no reliable indication of a link to the attacks in Belgium.

No-one at the prosecutor's office in Giessen could be reached for comment. A spokeswoman for the federal prosecutor's office did not immediately respond to a request for comment.-Reuters