OAKLAND — Federal prosecutors have secured a grand jury indictment against a U.S. Coast Guard commander who was arrested and charged in an alleged scheme to smuggle drugs in from Singapore.

James Silcox III, 41, was indicted Sept. 26 on three charges of importation of a Schedule IV narcotic, court records show. The criminal complaint against him alleges he received three shipments of Tramadol, a controlled substance and narcotic, to post office boxes over the summer.

Schedule IV drugs are defined by the federal government as drugs with a low potential for abuse and low risk of dependence.

According to the criminal complaint, on July 11, an 865-gram package from Singapore headed for an Alameda post office box was flagged by U.S. Customs and Border Protection officers at the U.S. Postal Service’s international mail facility at New York’s John F. Kennedy International Airport. Officers at the postal service’s San Francisco airmail facility intercepted another 650 200-milligram tablet Tramadol package from Singapore on Aug. 28, before receiving another package Sept. 13 that held 458 grams of Tramadol.

Silcox has requested the services of the federal public defender’s office, but prosecutors are fighting the move, saying that James Silcox and his wife — who is also a commander in the U.S. Coast Guard — make a combined $300,000 in “annual take-home pay” and are building a retirement home in Florida.

“That a defendant would rather not spend his money on an attorney does not mean he is ‘financially unable’ to obtain counsel,” Assistant U.S. Attorney Sarah Griswold wrote in a memorandum opposing Silcox’s retention of a public defender.

Silcox pleaded not guilty to the charges at a Sept. 30 arraignment hearing, court records show. He was released from jail the same day the charges were filed, according to the docket.

Staff writer George Kelly contributed to this report.