A man is being questioned under the Terrorism Act after he was arrested at Birmingham Airport on Monday night.
The 22-year-old was held on suspicion of being in possession of a document likely to be of use to a person committing or preparing an act of terrorism.
Police said the man is studying in the UK and has a student visa. He was arrested as he arrived in Birmingham on a flight from Dubai.
A West Midlands Police spokesman added: "The suspected document was found in his possession."
Police said the man was a Pakistani national and was studying in the UK at a "fully accredited institution".