The charges were filed by the U.S. Secret Service on Oct. 1 and allege that Maria Peguero used a debit card belonging to Sandra Hernandez to have nearly $180,000 in merchandise from Saks Fifth Avenue delivered to her Fife apartment between June 26, 2012 and Oct. 9, 2012.
The complaint does not identify Hernandez or his wife by name. However, a source familiar with the investigation, who spoke on condition of anonymity, confirmed their identities.
Randy Adamack, the Mariners' senior vice president for communications, said team officials are "aware of this pending police matter, but are not in a position to discuss it further."
Hernandez, affectionately known as "King Felix," is the Mariners' $19 million-a-year starting pitcher and winner of a Cy Young Award.
Peguero, 26, signed with the Mariners in 2005. He has spent the past three seasons splitting his time between the Mariners and their AAA Tacoma farm club. He played in just two major league games this past season, and 118 in Tacoma, where he batted .260 with 19 home runs and 83 RBI.
Maria Peguero, 22, is the youngest daughter of the late Pedro Borbon, who played major league baseball for 12 seasons - 10 for Cincinnati - as an acclaimed relief pitcher. Maria Peguero's federal public defender, Colin Fieman, was not working Friday and did not return a telephone message left at his office.
U.S. Magistrate Judge Karen Strombom ordered Peguero to reimburse the government $200 a month toward her defense.
The charges, filed by U.S. Secret Service Special Agent Ashleigh Audley, allege that Saks Fifth Avenue in New York began to scrutinize a series of online purchases made with a Morgan Stanley debit card through an account belonging to a "Jackie Peguero" because the billing and shipping addresses were different.
In addition to the charges, agents also executed a search warrant at the Pegueros' Fife apartment and seized dozens of items, according to court records.
The Secret Service oversees the federal cybercrime task force.
There were more than 60 transactions in all, ranging from a few hundred dollars to more than $11,000. On some days, as many as five separate purchases were made, according to a list contained in the complaint.
The charges say Morgan Stanley bank reimbursed the victims after the fraud was discovered.
According to the court documents, Maria Peguero "spent two or three days" at the Hernandezes' Bellevue home in May 2012 while Felix Hernandez was away. The Mariners had a long away stretch in the middle of the month, playing in New York, Boston, Cleveland and Denver.
According to the complaint, Sandra Hernandez told investigators she and Peguero shopped online during that time. The complaint indicates that Hernandez asked Peguero for help "due to (Hernandez's) limited understanding of the English language." Hernandez told investigators that Peguero had access to her credit cards during that time.
According to the investigation, Maria Peguero is associated with an email address, versacegoldbarbieyahoo.com, that was later traced to a Twitter account on which agents found photographs of Peguero wearing some of the items they believe were purchased illegally from Saks.
In one, Peguero is sitting next to a Gucci handbag identical to one purchased from Saks through the Hernandez account for $1,750.
According to the complaint, the purchases went on for more than three months, during which time Peguero contacted Sandra Hernandez to ask if she ever reviewed her debit-card statements. Hernandez told Peguero "that she did not usually review the bills because their finances were managed by a third party," according to the complaint.
Carlos Peguero told investigators that he was unaware of his wife's alleged purchases, the documents say.
The documents say Maria Peguero was arrested in 2010 by police in Edinburg, Texas, for allegedly shoplifting from a TJ Maxx store.
By agreement, the government and Peguero's attorney have waived her right to a speedy trial in the current case. Judge Strombom gave the government until Dec. 30 to seek an indictment by the grand jury.