The Economic and Financial Crimes Commission (EFCC) says Shehu Sani, former senator representing Kaduna central, has questions to answer.
The anti-graft agency said this in a statement on Friday.
The former senator was arrested two weeks ago for alleged extortion and he has been in custody since then.
The EFCC had accused Sani of collecting money from Sani Dauda, owner of ASD Motors, promising to pass it on to Ibrahim Magu, acting chairman of the anti-graft agency, to influence an investigation.
He was also alleged to have also said he could assist Dauda in influencing a case at the supreme court by bribing Ibrahim Muhammad, chief justice of Nigeria (CJN), and some other judges.
The CJN subsequently denied any links to the former senator.
In a statement on Friday, Tony Orilade, EFCC acting spokesman, said Sani’s rights are not being breached as there is a valid court order the anti-graft agency to keep him in custody.
Orilade said it is unfortunate that some people were defending the former senator, adding they “are not really conversant with his offence.”
According to him, Sani is not being investigated because he is a fierce critic of President Muhammadu Buhari.
“Invariably, claims in some quarters of the breach of his fundamental human rights are merely in the imagination of the purveyors of such claims,” the acting EFCC spokesman said.
“Let it be stated clearly that Senator Shehu Sani has questions to answer as regards his alleged involvement in name-dropping, and particularly that he obtained $25,000 from Alhaji Sani Dauda, the ASD Motors boss, in order to help shield him from investigations being carried out by the EFCC.
“For certain people to brazenly come out to defend a suspect who is being probed for a serious offence as the one committed by Sani shows that they are not really conversant with his offence.
“It is unfortunate that certain people are ready to do anything to support evil for pecuniary gains.”
On Wednesday, officials of the EFCC searched two houses belonging to the senator in Abuja. Sani later said he had been framed but he would not be silenced.