The lawyer Enes H Ermaner writes on X that they were arrested after a dawn raid where the police conducted a search of their homes.
Svenska Dagbladet describes Soykan as one of Turkey's leading investigative journalists, who has many times expressed himself in Swedish media about the gang war between, among others, Foxtrot and Rumba.
Agirel reports, according to the newspaper, a lot about corruption.
The Istanbul Chief Prosecutor's Office states that the allegations concern threats and extortion.
Several journalists have been detained in Turkey, where large protests have broken out against President Recep Tayyip Erdogan after his main rival, Istanbul's Mayor Ekrem Imamoglu, was arrested in the spring.
One of them is Swedish Joakim Medin, who was arrested at the end of March when he landed in Istanbul to report on the protests for the newspaper Dagens ETC.
The newspapers that the journalists work for have reported a lot about the protests, reports AP. The newspaper BirGun, which Timur Soykan writes for, states in a statement that "we all know" that they were arrested because of their journalism.
