A Nigerian activist accused by the authorities of plotting a violent insurrection has been detained in neighbouring Benin and is due to be sent back to Nigeria, according to reports in Nigerian media. Sunday Adeyemo, more commonly known in Nigeria by his nickname of Sunday Igboho, was arrested on Monday at Cotonou airport while on his way to Germany, according to media reports citing a lawyer and other Nigerian sources with links to Igboho. A spokesman for Nigeria's Department of State Services (DSS), a security agency that raided Igboho's residence in the southwestern city of Ibadan on July 1 and…