He said Buhari had at different times given different identities to the people believed to be masquerading as herdsmen and killing Nigerians in Benue and other states.
The ex-president was said to have stated this during his meeting with the leadership of the pan-Yoruba organisation, Afenifere, last week in Akure, the Ondo State capital.
According to Nigerian Tribune, more details of the meeting emerged on Sunday, May 27.
Obasanjo was said to have given a second reason as the gradual loss of public confidence in the capability of security agencies to curtail the herdsmen because of the body language of the president.
He reportedly said Buhari's body language and comments on the activities of the herdsmen are making the job of the security agencies difficult.
The newspaper quoted an 'impeccable source' who in turn quoted Obasanjo as saying; "He (Buhari) often speaks from both sides of the mouth on the issue of armed herdsmen killing of innocent citizens.
"At times, he would say the herdsmen are not Nigerians; that they are from Niger, Mali, Chad and other neighbouring countries.
"In the same breath, the president would say we should learn to live and cope with our neighbours, talking of the Middle Belt groups and that the crisis is an internal matter.
"At another time while in the United States, he said it was the fighters from Libya that were behind the killings. So, if the Nigerian military were to act, it will be against the position of the president. Therefore, the military had to be careful."
Another source was said to have quoted Obasanjo as saying that "Nigerians no longer have any regard for the military because of the activities of the killer herdsmen".
It was gathered that the former president also spoke against the claim by herdsmen and others that the anti-grazing law enacted by Benue State caused the massacre in the middle belt.
Obasanjo reportedly agreed with the position of Afenifere leaders that no matter how crooked any law was, once it was made by the parliament of a state, it was the duty of the security forces to enforce it, while the judiciary would do the interpretation.
Responding to a question of if the Afenifere leaders asked Obasanjo whether he had rallied the support other key individuals and groups in the country, the sources quoted OBJ to have said that his "meeting with the Afenifere was part of his efforts to coordinate national opinion against Buhari."
Obasanjo reportedly added that a number of leaders of the ruling APC, including governors that succeeded in winning the recent congresses of the party, had agreed to be part of the ongoing coalition against the president.
In what seems like Buhari's reaction to Obasanjo's move to stop his re-election bid, the Federal Government had on Tuesday, May 22, queried the former president over the spending of $16 billion on power projects during his administration.
The power project was done during the Obasanjo administration (1999-2006). It has been described as a mismanagement of public funds by observers and civic groups.
The Economic and Financial Crimes Commission (EFCC) operatives are said to have started gathering facts to would help in investigating the power project.
Obasanjo has since responded to the query, saying the Buhari administration can go ahead and probe him.