ABUJA — The Joint Admissions and Matriculation Board (JAMB) has dismissed a staff member for extorting candidates, according to its weekly bulletin released on Monday. The board did not name the employee. JAMB warned all its staff against any conduct that exploits candidates or the public, and said its crackdown on fraud now covers insiders as well as outside fraudsters. It described its policy as one of zero tolerance, applied regardless of rank.