The deputy leader of the party, Mehmet Cengiz, told Milliyet daily the prosecutor's office asked for four copies of their petition for official complaint.

"They told us that they are going to categorize the issue according to the type of the crimes and five prosecutors will investigate the issue," he added.

Once the investigation completed the chief prosecutor would decide to open a lawsuit or not.

Sources told Milliyet daily the Turkish prosecutors would contact their German interlocutors if needed.

A legal case was opened in Germany for the religious charity, Deniz Feneri, over claims of illegal financial transactions of donated funds and fraud.

According to the indictment of the case, donations were transferred or sent to pro-government Islamist media organs in Turkey even to Prime Minister's office.

The Workers Party demanded the prosecutors to open a criminal case for Prime Minister Tayyip Erdogan, the head of Turkish TV and radio watchdog -Zahid Akman-, the Deniz Feneri charity in Turkey, broadcaster Kanal 7.

Erdogan has immunity, while the premier's approval is needed for opening a lawsuit against Akman.