Istanbul ( CNN ) -- Turkey 's former military chief was behind bars Friday pending trial for his alleged role in a plot to overthrow the government . Gen. Ilker Basbug is the highest-ranking officer to be accused in a long-running tussle between the Islamic-backed government and Turkey 's secular establishment , defended by the military . Basbug was arrested and taken to Silivri prison after testifying for seven hours Thursday in an Istanbul court , Basbug 's lawyer Ilkay Sezer told reporters . He stands accused of involvement with the so-called Ergenekon network , a nationalist group that prosecutors say created dozens of websites disseminating propaganda aimed at bringing down the government of Prime Minister Recep Tayyip Erdogan . `` The 26th chief of general staff of the Turkish Republic is unfortunately arrested based on charges related to eliminating the government of Turkish Republic and establishing and leading a terrorist organization , '' Sezer said . Basbug retired as commander of the Turkish armed forces in 2010 . He is the latest in a long line of military staff who stands accused of plotting against the government . A probe was launched in 2007 , after the discovery of a stash of grenades and bomb-making materials in Istanbul . It led to waves of arrests and several court cases involving both civilians and former and active-duty officers . More than 300 people have been arrested in connection with Ergenekon . Among them are 97 journalists , according to the Turkish Press Union . The government 's crackdown has polarized Turkish society , which has seen the military overthrow four governments in the past 50 years . Some view the government 's actions in curbing military power as important steps to democratization in Turkey , a candidate for European Union membership . But critics say the investigation is a political witch hunt . They accuse Erdogan , an observant Muslim , of silencing his opponents and emasculating the secular establishment , including the military . Last July , Turkey 's top four military officers resigned after a squabble with the government over the fate of officers jailed in the alleged plot against the Justice and Development Party . Friday , Turkish President Abdullah Gul told journalists that Basbug 's arrest did not prove guilt . `` No one can be declared guilty before a decision of the court , '' Gul said . `` Everyone is equal in the court of law . This is a legal process . '' CNN 's Yesim Comert and Talia Kayali contributed to this report .
Gen. Ilker Basbug is the highest-ranking officer to be accused . The Islamic-backed government alleges a military plot . Critics say the government wants to emasculate the military .