BOSTON — A Hyannis man and two other men were indicted on drug charges in federal court Wednesday after authorities seized more than a half-kilogram of fentanyl, according to the U.S. Justice Department.

Steven Marshall, 31; Hilario Yogey Mota-Bernabel, 26, a Dominican national living in New Bedford; and Miki Michael Mota-Bernabel, 29, a Dominican national living in Providence, Rhode Island, were charged with conspiracy to distribute and possess with the intent to distribute fentanyl and possession with intent to distribute and distribution of fentanyl, according to a statement from the department.

Investigators had Marshall under surveillance in January and February as he traveled to New Bedford to buy fentanyl from Hilario Yogey Mota-Bernabel, according to the statement. They stopped him after a drug pickup March 1, searched his vehicle and seized about 125 grams of fentanyl, the statement says.

Agents also made four controlled purchases of about 100 grams of fentanyl each from Hilario Yogey Mota-Bernabel in March and April, according to the statement. Miki Michael Mota-Bernabel acted as courier for one of the purchases, the statement says.

A search of Hilario Yogey Mota-Bernabel’s residence and stash house resulted in the seizure of more than 350 grams of suspected fentanyl, $12,395 and other drug-related items, according to the statement.

Court documents indicate the Mota-Bernabels entered the country illegally, the statement says.

The Mota-Bernabels were arrested May 22 and Marshall was arrested by federal authorities Wednesday, after previously being arrested by Barnstable police and arraigned in Barnstable District Court.