"The fight against corruption must be relentless and continuous because the forces of corruption are determined forces," the president of the African nation that regularly tops the global list of most corrupt countries, said on Friday.
"Unless you continue to check on them, they will do all sorts of things, including blackmailing, using subterfuge, even threat and intimidation to get themselves off the public hook," Obasanjo said.
Obasanjo's call for transparency is an attempt to repair Nigeria's tainted image. But the task at hand is difficult.
The president said he would introduce an initiative urging oil and other companies involved in mineral extraction, such as gold, to open their accounts to scrutiny.
The idea is that Nigerian companies would reveal how much they received and their foreign partners would publish how much they paid.
"The fight against corruption must be relentless and continuous because the forces of corruption are determined forces"
"When you have received $10 million but the others paid $12 million, where has the two million gone? When the two societies publish the accounts, this is truly transparent," Obasanjo reminded.
The president was speaking at a press conference organised by global corruption watchdog Transparency International.
Last month Transparency International released its world wide annual graft index, ranking Nigeria second only to Bangladesh ias the most corrupt.
Never short of pledges, Obasanjo ironically is a founder member of the Transparency International.
But in the five years he has been in power, not a single senior figure has been convicted of corruption.