The EFCC said the billboard advert is an “offensive political campaign message”.
The EFCC accused Mr Nnamdi of publishing an “offensive political campaign message” on a billboard in Enugu, with the commission’s name and logo on it.
The message on the billboard reads, ‘2023: Enugu PDP Learn From 2007 Election… EFCC Is Coming With Koboko On Corrupt Candidates’.
The EFCC arrested Mr Nnamdi on Saturday, according to the commission’s spokesperson, Wilson Uwujaren.
Mr Effiong, however, said Mr Nnamdi committed no offence and, therefore, should be released immediately by the anti-graft commission.
He also asked the EFCC to apologise to him.
The lawyer, in a statement on Sunday, said the reasons given by the EFCC to justify the arrest of Mr Namdi were “baseless, false and legally unfounded”.
“The use of the logo or name of the EFCC is in itself not a criminal offence,” Mr Effiong said.
“There is no Section of the Economic and Financial Crimes Commission (Establishment) Act, 2004 that makes the mere use of the name or logo of the EFCC, without more, a criminal offence.
“Section 6 (q) of the EFCC Act provides for the functions of the Commission, which includes: ‘carrying out and sustaining rigorous public and enlightenment campaigns against economic and financial crimes within and outside Nigeria.’
“By Section 24 of the Constitution of the Federal Republic of Nigeria, 1999 (as amended), citizens have a constitutional duty to assist law enforcement agencies in the discharge of their functions,” he said.
Mr Effiong dismissed as “false and misleading” the claim by the EFCC that the billboards at Otigba and Zik Avenue Junctions in Enugu could threaten the aspiration of some politicians in the state in the buildup to the 2023 general election.
The lawyer said the message in the billboard is positive and promotes the agency’s war against corruption.
“It is rather ironic that the same EFCC that claims to be investigating politicians regarding the source of the humongous sums they are using to buy nomination forms, is now antagonising patriotic citizens who are warning corrupt politicians to be mindful of the same EFCC.”
Mr Effiong described the arrest as “needless persecution and distraction”.
He said the commission should rather commend the group that sponsored the advert.