There have been reports of fake Turkish Visas being issued to UK holidaymakers and ABTA have warned that visas should only be obtained from the official Turkish e-Visa website
British nationals need a visa to travel to Turkey whether as a tourist or on business (except for cruise ship passengers with UK passports entering the country for a day trip, remaining in the port of embarkation and returning to the ship the same day).
Visas can still be obtained on arrival but this service is due to be phased out.
For more information check the Foreign & Commonwealth Office travel advice pages