A constable from Junagadh district has been arrested in connection with the alleged murder of RTI activist and green crusader Amit Jethwa here, the police said on Tuesday. "We have arrested Bahadursinh Wadher, a police constable from Jungadh in connection with the killing of Jethwa. Wadher was posted in the Gir-Gadhada region of Junagadh," DCP (crime), Himanshu Shukla told PTI.