President Donald Trump’s administration has asked federal courts to strip Nigerian-born George Oyakhire and Adeyeye Ariyo Akambi of their U.S. citizenship over alleged identity fraud amid its immigration crackdown.

The Department of Justice said in a statement on Friday that it had begun legal processes in district courts to denaturalise Messrs Oyakhire and Akambi, as well as 11 other foreign-born Americans, over allegations of identity fraud, war crimes, sexual abuse, and support for terrorism.

Mr Oyakhire, whom the DoJ said was “naturalised under a false identity,” first entered the United States on October 18, 1986, with a visa bearing his real name, George Ofuan Oyakhire.

According to the department, Mr Oyakhire, 66, later used a fake name, “Oliver Bennett Oyakhire,” and a false birth date to obtain temporary resident status on September 2, 1988, and eventually obtained permanent residency on December 1, 1990.

“On September 12, 1995, again using the false Oliver Bennett Oyakhire identity, Mr Oyakhire filed an application for naturalisation, which was approved on March 22, 1996. On April 22, 1996, Mr Oyakhire became a naturalised citizen under the false name Oliver Bennett Oyakhire,” the department said.

For Mr Akambi, 65, after his deportation from the U.S. in 2000, he used a different identity to obtain permanent residency and was naturalised after he “concealed his prior removal.”

“Because Mr Akambi obtained his citizenship after concealing these facts and misrepresented his eligibility for citizenship, the United States is seeking to revoke his certificate of naturalisation,” the department said.

Among those to be denaturalised are 48-year-old Iraqi-born Ali Yousif Ahmed Al-Nouri, accused of illegally procuring his naturalisation; Oscar Alberto Pelaez, 75, from Colombia, who allegedly abused a minor sexually on several occasions; and a Moroccan, Khalid Ouazzani, 48, accused of providing false testimony during citizenship processes.

The DoJ is also seeking to denaturalise Somali-born Salah Osman Ahmed, 43, for “providing material support to terrorists”; Baboucarr Mboob, 58, a native of The Gambia, accused of concealing his involvement in war crimes during his naturalisation process; and Kevin Robin Suarez, 31, born in Bolivia, for concealing facts during his citizenship proceedings.

Others include Abduvosit Razikov, a native of Uzbekistan, accused of immigration fraud; 28-year-old Abdallah Osman Sheikh from Kenya, accused of unlawfully obtaining citizenship after concealing “a material fact”; and Indian-born Debashis Ghosh, accused of investment fraud.

Also to be denaturalised are 53-year-old Pin He from China for alleged identity fraud, and 75-year-old Victor Manuel Rocha, a native of Colombia, for lying during his naturalisation process; he later admitted, during criminal proceedings, to espionage activities for Cuba in 1973, before his naturalisation in 1978.

“Individuals implicated in committing fraud, heinous crimes such as sexual abuse or expressing support for terrorism should never have been naturalised as United States citizens,” said acting Attorney General Todd Blanche. 

He added, “The Trump administration is taking action to correct these egregious violations of our immigration system.”

Mr Blanche vowed that individuals found to have concealed criminal histories during the naturalisation process “will face the fullest extent of the law.”

Assistant Attorney General Brett A. Shumate of the Justice Department’s Civil Division echoed Mr Blanche’s stance, describing the individuals’ criminal histories as “disturbing” and stating they should never have been granted citizenship.

He said the DoJ will continue to pursue denaturalisation cases and reiterated its commitment to revoking citizenship obtained through fraud or misrepresentation.

Citizenship obtained through naturalisation may be revoked under the Immigration and Nationality Act if individuals obtain it illegally, conceal a material fact, or willfully misrepresent facts during naturalisation proceedings. 

The New York Times reported in April that the DoJ had identified 384 foreign-born U.S. citizens for possible denaturalisation.