The delay in the results from Zimbabwe's election is "a joke" and African leaders should press President Robert Mugabe's government to release them at once, a prominent African good governance campaigner said on Friday.

Zimbabwe's opposition says its leader Morgan Tsvangirai won the March 29 presidential poll, and Mugabe, who has ruled the southern African state since independence in 1980, has come under international criticism over the delay to the results.

Sudanese-born telecommunications entrepreneur Mo Ibrahim, who has established a $5 million prize to reward good government in Africa, said it was unacceptable that the outcome of the ballot was still not known three weeks after it was held.

"It's a joke the results should be released immediately," Ibrahim, one of Africa's most successful businessmen who is now lobbying for cleaner government on the continent, told Reuters during a visit to Senegal.

Ibrahim, who in 2006 set up a foundation dedicated to improving African leadership, said the continent's heads of state and government were not doing enough to force Zimbabwean authorities to announce the presidential poll outcome.

"I think they should be putting the pressure on," he said.

Tsvangirai's Movement for Democratic Change (MDC), which beat Mugabe's ruling ZANU-PF party in a parallel parliamentary vote last month, accuses the Zimbabwean leader of using violence to try to rig a victory in an expected presidential run-off vote against the opposition leader.

The inaugural $5 million Ibrahim Prize for Achievement in African Leadership - the world's largest annual individual prize - was awarded in 2007 to the former president of Mozambique, Joaquim Chissano.

"NO MAGIC WAND"

Ibrahim's Foundation last year started an Index of African Governance, which ranks 48 Sub-Saharan African states on the quality of governance based on a range of categories including security , rule of law, human rights and human development.

In the 2007 Index, Zimbabwe ranks 31, behind Mauritius at No. 1 and South Africa at 5, but Zimbabwe scores highly on safety and security and comes ahead of Nigeria at 37, Liberia at 43, Sudan at 45 and Somalia last at 48.

Ibrahim told a news conference earlier that economic development in Africa depended on good government.

"Without good governance, forget it, nothing will happen. You can have all the aid and oil in the world, and people will still live in poverty and you'll still have genocide," he said.

"Bad governance here can lead to the death of millions of people," Ibrahim added.

He acknowledged his campaign would have to overcome years of resistance to outside censure by long-serving African leaders, whom critics accuse of closing ranks and turning a blind eye to graft, abuses and genocide committed by some of their peers.

"We don't think that we just have a magic wand to wave and suddenly Africa will turn into an oasis (of good governance) this will be a long road," Ibrahim said.

He added his campaign was seeking to mobilise ordinary Africans to demand good governance from their leaders.

"No one can accuse us of being foreign colonisers or imperialists," he said.

Former United Nations Commissioner for Human Rights Mary Robinson, who is on the board of Ibrahim's foundation, said she believed the governance index could promote change in Africa. "We hope over time this index will be a real tool for civil society," added Robinson, a former president of Ireland.