The Mo Ibrahim Foundation announced Thursday that no former African leader had met the “very high bar” for one of the world’s richest prizes. The Ibrahim Prize has been awarded just four times in the decade since it was established.

Former President Goodluck Jonathan failed to win the prestigious $5 million Mo Ibrahim Prize for Achievement in African Leadership despite meeting a key criterion.

Although, Jonathan seems to have met the Prize criteria which includes Former African Executive Head of State or Government, left office in the last three years, democratically elected, served his or her constitutionally mandated term, demonstrated exceptional leadership; it is unclear why he wasn’t given.

Allegations of massive corruption under his administration presently being investigated and prosecuted by the EFCC may have cost Jonathan the prize.

So far, only the former presidents of Mozambique, Joaquim Chissano; Botswana’s Festus Mogae; Namibia’s Hifikepunye Pohamba; and Pedro Piers of Cape Verde have clinched the award. Ex-South African President Nelson Mandela was awarded an honorary prize in 2007.

The founder, Mo Ibrahim speaks to Newsday on why there was no winner.

#MoIbrahim‘s speaks to Newsday on the Prize. Listen to his thoughts https://t.co/hpvhYiqDR3

— Mo Ibrahim Fdn (@Mo_IbrahimFdn) June 17, 2016