A man has been arrested on suspicion of terrorism offences at Heathrow Airport.
The 26-year-old was arrested by the Metropolitan Police counter-terrorism command on Thursday as he arrived on a flight from Turkey.
Scotland Yard said the unnamed man was held on suspicion of preparation of terrorist acts. The arrest was Syria-related, the force added.
Turkey Interior Ministry said it had deported eight Islamic State suspects – one Briton and seven Germans.
It did not identify any of the suspects. The Home Office also refused to disclose any details, saying it did not comment on individual cases.
The BBC has been told the arrested man was the deported British IS suspect.