New Haven — A 36-year-old Nigerian man pleaded guilty Thursday in U.S. District Court to one count of conspiracy to commit wire fraud in relation to a phishing scheme against employees at Groton Public Schools.

Olukayode Ibrahim Lawal, 36, who was most recently living in Smyrna, Ga., is scheduled to be sentenced March 14, 2019, according to the news release. The charge carries a maximum sentence of 20 years.

In March 2017, a Groton Schools employee got an email from a sender falsely posing as Superintendent Michael Graner that requested W-2 tax information for all staff, according to the release. The employee, who thought the email was from Graner, replied with the W-2 information of 1,300 employees.

According to an affidavit, the email stated: "I need W-2copy list of all Employees wage and tax statement for 2016. Kindly prepare and attach the lists in PDF file type and email them to me for review as soon as possible. Thanks Michael."

About a hundred Forms 1040 then were filed with the IRS in the names of victims and claimed $491,737 in refunds, according to the news release. Three were processed and "$23,543 in fraudulently-obtained funds were electronically deposited into various bank accounts," while the "other returns were not processed because they were suspected of being fraudulent."

"Lawal controlled or used certain email accounts involved in this phishing scheme," the release states. "A co-conspirator of Lawal sent personal identifying information, including names and Social Security Numbers, of at least 10 employees to an email account that Lawal used. Lawal then sent the victims’ personal identifying information to another co-conspirator."

In February 2017, about 103 employees at Sacred Heart Academy in Hamden were victims of another phishing scheme, and "33 victims had fraudulent tax returns filed electronically with the IRS, claiming refunds in the amount of $314,184. The returns were not processed because they were suspected of being fraudulent."

Lawal came to the U.S. on a visitor’s visa on Nov. 24, 2016, but did not leave when he was scheduled, on Dec. 1, 2016, according to the release. He has been detained since he was arrested May 9, 2018.

The Federal Bureau of Investigation and the Internal Revenue Service, Criminal Investigation Division are investigating, the release states. Assistant U.S. Attorney Sarala V. Nagala is prosecuting the case.

The U.S. Attorney's Office for the Northern District of Georgia also assisted, the release states.

In September, another man, Daniel Adekunle Ojo, 34, who is from Nigeria and was living in Durham, N.C., was sentenced to 32 months in prison followed by three years of supervised release in connection to the phishing scheme against Groton Schools, along with schemes against schools in Glastonbury and Bloomington, Minn.