This article is more than 6 years old

This article is more than 6 years old

Eight people detained for questioning this week as part of a massive corruption investigation targeting allies of the prime minister, Recep Tayyip Erdogan, have been formally arrested, the state-run news agency reported.

The inquiry has also drawn in sons of three government ministers and comes amid a power struggle between Erdogan's government and an influential US-based Muslim cleric, Fetullah Gulen, who has a strong following in Turkey and is believed to have leverage within the country's police force and judiciary.

The Anadolu Agency said the eight who were formerly arrested included the brother of the mayor of an Istanbul district that is an Erdogan stronghold. They face possible bribery charges, according to the agency.

At least 27 other people were being questioned by court officials on Friday.

Erdogan has denounced the investigation and the detention of cabinet ministers' sons as a plot to harm his government and has vowed to go after "gangs" of alleged conspirators.

The deputy prime minister, Bekir Bozdag, said on Friday the investigation and arrests were aimed at discrediting the party before elections in 2014.

"These dirty games, operations and traps are being carried out to break the party's bonds of love with the people and affect the local and presidential elections," he said on his Twitter account.

Fourteen top police officials at the national police headquarters in Ankara were removed from office on Friday. That is in addition to more than two dozen who have been relieved of their posts since Tuesday's police raids rounded up more than 50 people for questioning.

Opposition parties have denounced the police dismissals as an attempt by Erdogan's party to cover up the scandal.

"The AKP has descended with all its might on those who are combatting corruption and bribery," said Ozcan Yenicer, a legislator from Turkey's nationalist party. "At this point, no one should expect anything to come out of these probes."