Police on Wednesday searched the homes of four Turkish Muslim preachers on suspicion they spied for President Recep Tayyip Erdogan’s government, officials said.

The imams are accused of reporting on Turkish followers of US-based Islamic preacher Fethullah Gulen, who Erdogan blames for last July’s failed coup attempt against him.

The four imams allegedly passed on information through the Turkish consulate in the western city of Cologne to the Turkish Religious Affairs Directorate, known as Diyanet, prosecutors said.

“The purpose of today’s searches is to gather further evidence on the alleged activities of the accused,” prosecutors said after the raids in the western states of North Rhine-Westphalia and Rhineland-Palatinate.

News site Spiegel online reported the imams belong to Ditib, an organisation controlled by Ankara that manages some 900 mosques or religious communities in Germany.

The Erdogan government has cracked down hard on followers of Gulen, who denies he was behind the attempted putsch.

More than 41,000 people have been arrested over their suspected links to Gulen’s movement, and 100,000 fired or suspended. Many of them are teachers, police, magistrates and journalists

The government says the purges are necessary to clean the state of the “virus” of Gulen’s movement, which encourages its members to work in public services.

Human rights activists have fiercely criticized the magnitude of the crackdown, saying it has gone well beyond alleged coup plotters.

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