A top Turkish court yesterday endorsed the acquittal of a controversial Muslim preacher and writer on charges of plotting to establish Shariah or Islamic law in secular Turkey.

The Appeals Court ruling opened the way for Fethullah Gulen to return to Turkey from exile in the United States, NTV private broadcaster said.

Gulen, known for his philanthropy and his calls for dialogue between faiths, has a wide following in Turkey but some powerful secularists, including in the army, have long accused him of plotting to destroy the secular state.

In its ruling, the Appeals Court upheld an earlier verdict from a lower court, saying Gulen and his followers were not guilty of forming an illegal terrorist organisation that aimed to introduce shariah law using force and violence.

The court case against Gulen, now 66, was based on videotapes that purportedly showed him weeping and fainting with religious ecstasy and urging supporters holding public office in Turkey not to show their hand too early. Gulen, the author of dozens of books on religion, science and philosophy, said the videotapes had been deliberately doctored to show his remarks out of context.

Gulen's movement runs schools in Turkey, the Balkans and central Asia. His network also includes a university, a newspaper and a number of businesses. In his teachings, Gulen stresses the importance of modern science and technology. Gulen has good relations with Turkey's ruling centre-right AK Party.