The EFCC has blocked the former minister's plan to defend herself in a fraud case.
The embattled former minister had filed a motion in front of Justice Rilwan Aikawa to be added as a defendant in the fraud trial involving her associates Dele Belgore (SAN) and former Minister of National Planning, Prof. Abubakar Suleiman.
She had urged the court to compel the office of the Attorney General of the Federation to bring her back from the United Kingdom to enter a plea for the charges.
During the application's hearing on Monday, the EFCC opposed the motion, calling it "misconceived and belated" as well as an attempt to slow down the trial.
The prosecuting counsel, Mr Rotimi Oyedepo, said, "The application is frivolous and is intended to annoy the parties. This application is intended to delay this case."
Belgore's counsel, Mr Ebun Shofunde (SAN), also opposed Diezani's application, arguing that her presence is irrelevant to the court's proceedings.
He said, "Without the applicant being a party, what the court will determine is the guilt or innocence of the first and second defendants. The court does not require the presence of the applicant to determine their guilt or innocence."
Diezani had filed the application on October 3 seeking to be named as a defendant by the prosecution since she was mentioned in the money laundering charge sheet.
She said she was eager to return to the country to defend herself, contrary to claims by the EFCC that she was dodging investigators.
On Monday, her counsel, Mr Onyechi Ikpeazu, argued that she was more or less a defendant in the case since she was mentioned as a person of interest who was at large.
In the charge, Diezani was alleged to have conspired with Belgore and Suleiman on or about March 27, 2015, to directly take possession of N450 million, which they reasonably ought to have known formed part of proceeds of an unlawful act.
Ikpeazu said, "It is the fundamental right of the applicant that a criminal proceeding of this nature should not go on in her absence."
He further argued that if the prosecution is uninterested in naming her as a defendant, then her named should be completely withdrawn from the charge.
"We have no objection if her name is extracted from the charge and the case goes on," he added.
Justice Aikawa will make a decision on the application on Wednesday, November 1.
The main defendants in the N450m money laundering trial, Belgore and Prof. Suleiman, are both standing trial for allegedly collecting the sum of money from Diezani while she was minister, and laundering it in the the build-up to the 2015 general elections.
They were both arraigned on five counts by the EFCC who filed the charges and mentioned Diezani's name without including her as a defendant.
The defendants pleaded ''Not Guilty'' to the allegations of making a cash transaction of N450m on March 27, 2015, without going through any financial institution.
With a trail of corruption allegations against her, Diezani has been holed up in the United Kingdom where she is also waiting to stand trial for alleged bribery, corruption and money laundering.