The State Security Service on Monday evening said it had started studying a court order on Ibrahim El-Zakzaky for compliance.
The Kaduna State High Court on Monday morning granted the Shiite leader and his wife, both held in violation of court bail since 2015, a leave to travel to India for medical treatment.
Mr El-Zakzaky had fallen ill in custody since he was arrested in December 2015 during the Nigerian Army massacre of hundreds of Shiite in Zaria.
"This is to inform the public that the Department of State Services (DSS) has received the order granting Ibrahim EL-ZAKZAKY leave to travel to India for medical treatment.
"Consequently, the Service is liaising with relevant stakeholders to ensure compliance.
"Conformity with the order is in line with the Service's avowed commitment to the Rule of Law inherent in a democracy," SSS spokesperson, Peter Afunanya, said in a statement.