The Central Bureau of Investigation on Saturday served notice to Dera Sacha Sauda chief Gurmeet Ram Rahim Singh, asking him to appear before a court in Ambala on August 31 in connection with three chargesheets filed against him, including that of alleged sexual exploitation of sadhvis.

A special CBI team, escorted by heavily armed police, reached the Dera headquarters in Sirsa on Saturday morning and was made to wait for over three hours before the notice could be served to the Dera chief in his gufa (cave), CBI sources said.

The team had to serve the notice for his personal appearance before a designated court in Ambala on August 31 so that it could proceed in the three cases in which it has filed chargesheets against him.

The CBI named Singh in three cases -- murders of Dera manager Ranjit Singh and journalist Ram Chander Chattrapati and alleged sexual exploitation of sadhvis.