The diocese distanced itself from the ordinations conferred by the diocesan bishop in mid-July after it became known that the order to which the men allegedly belonged did not even exist.
"At no time were they known to be members of our diocese. After the ordination, they went to their community. We have nothing to do with any of them and were deceived," reads the statement published by the published by the CISA agency.
The faithful had realised during the ordination service, but only after the ordination ceremony, that one of the candidates had previously pretended to be a priest and presided at masses.
The diocese will now "look for appropriate canonical steps to address the unfortunate situation".
The matter will be investigated further.
Measures are to be found for the future to ensure that such events do not happen again.
In its statement, the diocese explained how the erroneous consecration could have happened.
A man by the name of Stephen Obioma Nwaigwe claimed to be the superior general of a "Congregation of Paraclete Missionaries" and asked for the candidates to be ordained.
The man presented forged documents that were supposed to prove the establishment of the community as an institute under diocesan law in the diocese of Morogoro in Tanzania in 2016.
He also referred to branches and social institutions of the alleged order in other Nigerian dioceses.
Nwaigwe later submitted the documents and evidence required by canon law for the four candidates for ordination. However, these documents were also forged.
As a rule, religious orders cannot ordain their deacons and priests themselves, as the sacrament of ordination can only be administered by bishops.
It is still unclear whether the ordinations of the four men were valid and whether they are actually deacons. To verify the validity of an ordination, canon law provides for a specially regulated ordination validation procedure. Such a procedure can be initiated by the Ordinary of the diocese in which a cleric was ordained.
An office set up for this purpose at the Court of the Roman Rota, the second highest ecclesiastical court, is responsible for conducting the proceedings. As soon as such proceedings are initiated, the cleric concerned may no longer practise his ordination.
Reasons for determining the invalidity of an ordination include defects in the form of the ordination act and in the intention of the recipient to actually receive an ordination. Ordinations are also invalid if the applicant for ordination is unbaptised.