AP
Among those remanded in custody was the brother of the mayor of Istanbul's historic Fatih district, Hurriyet daily said. It was not clear who else had been arrested.
Mayor Fatih Demir was detained this week, and on Friday was in court to hear if he would be arrested or freed, Dogan News Agency said.
A total of about 50 people, including at least one son of a cabinet minister and billionaire construction magnate Ali Agaoglu, were at the Istanbul court, Hurriyet said.
The operation, unprecedented in scope, began this week with the detention of scores of people seen as close to the government, has struck at the heart of Turkey's ruling elite and roiled financial markets.
Dozens of police chiefs have been removed from their posts, accused of abuse of office for keeping the investigation quiet from higher level officials in security institutions.
More officials fired
ISTANBUL (Reuters) - Turkey removed another 14 heads of police units from their posts amid an ongoing probe into allegations of official corruption and bribery, local media reported on Friday.
Turkey had already removed a dozen senior police officials, including Istanbul police chief Huseyin Capkin, in an investigation Prime Minister Tayyip Erdogan has called a "dirty operation" aimed at undermining his rule.
Fourteen unit heads at the Turkish National Police headquarters in Ankara were removed from their duty, news television channels NTV and CNN Turk reported.