"There was nothing suspicious found and he has been allowed to continue his journey," interior ministry spokesman Karl-Heinz Grundboeck told AFP.
"The only thing outstanding is a detailed analysis of his mobile phone," he said of the incident which took place on Saturday.
A woman sitting next to him on the London-bound plane had alerted cabin crew after seeing what she thought could be messages related to the extremist Islamic State (IS) group on his phone.
The incident comes as Europe steps up security following Tuesday's bombings in Brussels, in which three suicide bombers killed 28 people in a series of attacks claimed by IS.