The alleged lover of the pregnant missing wife of a U.S. Marine based in Southern California has been arrested in Alaska on a federal warrant, according to law enforcement sources.

According to CBS Los Angeles, Cynthia Kott, a booking clerk at the Anchorage Correctional Complex, said Monday that Cpl. Christopher Brandon Lee was arrested at 10 p.m. Sunday.

CBS also reported that a law enforcement official who was not authorized to speak before a noon news conference and requested anonymity said the arrest was in the killing of Corwin. Lee has been the subject of the investigation into the case of missing Marine wife Erin Corwin, who disappeared June 28 after leaving her home in Twentynine Palms.

Lee, then a Marine corporal, was arrested July 4 after a search warrant was served at a home in Yucca Valley and then released on bail two days later, the San Bernardino Sheriff's Department said in a statement.

A detective's affidavit shows the investigation is focusing on the 24-year-old Lee, who authorities now say Corwin was having an affair with. There is also speculation that Lee may have been the father of Corwin's child.

Sheriff's spokeswoman Jodi Miller said Lee was arrested as a result of a search warrant in an ongoing investigation, but would not give more details.

Lee's name became associated with the case of the missing Marine wife after court documents showed on the day she disappeared, 20-year-old Erin Corwin had planned to meet with Christopher Brandon Lee to spend a "special day together" on a hunting trip.

Corwin, who is three months pregnant, was last last seen around 7 a.m. on June 28 at the Twentynine Palms home she shared with her husband, Lance Cpl. Jonathan Corwin.

Her Marine husband told investigators with the San Bernardino County Sheriff’s Department that his wife was setting out to explore Joshua Tree National Park in anticipation of an upcoming family visit.

Jonathan Corwin reported his wife missing the next day. Police located her 2013 Toyota Corolla in Twentynine Palms two days later, on June 30.

According to court documents obtained by the Desert Sun, detectives believe the day trip was actually meant to celebrate Corwin's pregnancy, but that Lee was concerned his wife would learn of his affair.

"It is highly likely that Erin could have been harmed by an unknown firearm," investigators reportedly wrote in court documents. "Sometime after Erin left with Lee, her phone was deactivated (turned off). Detectives believe if Erin was injured and left at an undisclosed location, she would not (be) able to call for help."

Investigators now believe the missing pregnant wife of a California-based Marine may have been shot while hunting with the married ex-Marine, according to reports.

Court documents also show that Corwin had admitted to a friend she was having an affair with Lee in a series of text messages.

An affidavit filed by Detective Corey Emom states that text messages were sent by Erin Corwin to a friend, in which Corwin indicated that she and Lee were in a romantic relationship, and that they had planned a day trip on June 28.

The affidavit also states Lee's wife, Nichole Lee, told a friend police 'would never find the body' and that she scolded her husband for 'not being able to keep his lies straight when he was interviewed by detectives because he was dumb.'

Lee has told authorities he was not with Corwin on the day she disappeared, but said he was out hunting in Joshua Tree National Park, according to the Desert Sun.

A day after Lee's arrest, he was honorably discharged after six years in the Marine Corps, the Desert Sun reported.