Istanbul - A Turkish colonel has been arrested on suspicion of plotting to undermine the ruling Islamist AK Party, Istanbul media reports said Wednesday.

Dursun Cicek has been accused of membership of Egenekon, a supposed right-wing underground organisation agitating for a military coup and the fall of Prime Minister Recep Tayyip Erdogan's government.

The arrest comes amid renewed tensions between the mildly-Islamist AK Party and the military, after a local newspaper reported an army plot to undermine the government through a media campaign.

Cicek has been accused in the media of drafting a document to further the suspected coup plan, a charge which Cicek has denied. He has said that the signature on a document was a fake.

The document purportedly described how the AK Party, as well as the movement of controversial Muslim scholar Fethullah Gulen could be undermined, by provoking tensions within the two organizations.

Details of how to plant weapons in buildings used by the Gulen movement were also laid out, in an attempt to implicate it in terrorist activity.

On Tuesday, Turkish state prosecutors questioned nine high-ranking officers in relation to ongoing investigations into Ergenekon.

The investigation into the so-called Ergenekon plot to overthrow the government has seen more than 150 people charged, including retired generals, serving officers, academics and journalists.

It was through assassinations and other destabilizing attacks that the group hoped to create the chaos necessary to allow the military to launch a coup in 2009 on the basis that it was bringing order back to society, the Turkish authorities allege.

Ergenekon is the name that prosecutors allege the group called themselves and refers to a mythical Turkic homeland in central Asia.

Those taken into custody earlier are currently on trial in Istanbul. Prosecutors at the trial have said that the staunchly secularist and nationalist group was angry at what they believe is the government's watering down of secular laws and its erosion of national sovereignty in Turkey's bid to join the European Union.

Opposition figures have described the trial as a witch hunt carried out by the government as revenge for a failed attempt to have the ruling Justice and Development Party
(AKP) closed down, or as a way to take attention away from its alleged attempts to undermine the secular state and implement Sharia (Islamic) law.(dpa)