The Kaduna state government says Nasir El-Rufai, its governor, did not describe Buhari as lacking the mental and physical capacity to lead Nigeria.
The remark had been attributed to the governor in a report published by an online platform which many readers erroneously assumed was TheCable.
In a statement on Saturday, Samuel Aruwan, Kaduna commissioner for internal security, said the claim is false.
He said those behind the publication seek to create “tension and confusion in the nation’s polity”.
Aruwan urged members of the public to disregard the platform “trying to pass off as a popular online newspaper to spread their mischief”.
“A mischievous online report is circulating fake comments on President Muhammad Buhari which they falsely attribute to Governor Nasir El-Rufai,” the statement reads.
“The intention of the forces behind the fake and mischievous news, for reasons best known to them, is to create tension and confusion in the nation’s polity.
“The entire content is fabricated, and they are trying to pass off as a popular online newspaper to spread their mischief.
“The Kaduna State Government urges the general public to disregard that publication and treat it as the vile lie that it is.”