There is no winner this year for the world's most valuable individual prize - the Mo Ibrahim prize for good governance in Africa.
The $5m (£3.2m) prize is supposed to be awarded each year to a democratically elected leader who governed well, raised living standards and then voluntarily left office.
The panel said no candidate had met all of the criteria - as in 2009 and 2010.
Last year, Cape Verde President Pedro Verona Pires won the prize.
He led the fight against Portuguese colonialism, introduced multi-party politics and was praised raising for living standards.
The $5m prize is spread over 10 years and is followed by $200,000 a year for life.
Announcing the decision, Mr Ibrahim said: "You make your bed, you have to lie on it. If we said we're going to have a prize for exceptional leadership, we have to stick to that. We are not going to compromise."
"We are not just in the business of positive messages - we would lose our credibility," the AFP news agency quotes him as saying.
"The prize committee reviewed a number of candidates but none met all of the criteria needed to win the prize," said committee member Salim Ahmed Salim.
The two other winners in the six years since the prize was launched were Botswana's President Festus Mogae and Mozambique's Joaquim Chissano.
Earlier this month, Mr Ibrahim's foundation announced a special $1m award to Archbishop Desmond Tutu for "speaking truth to power".
The London-based body called the cleric "one of Africa's great voices for justice, freedom, democracy and responsible, responsive government".
Sudan-born telecoms entrepreneur Mr Ibrahim says the good governance prize is needed because many leaders of sub-Saharan African countries come from poor backgrounds and are tempted to hang on to power for fear that poverty awaits them when they leave office.