CHARLESTON, S.C. — An FBI agent, citing a statement from a prison inmate, says a teenage girl who disappeared from Myrtle Beach seven years ago was abducted, gang-raped, shot to death and thrown into an alligator-infested swamp.

Agent Gerrick Munoz this week gave the first detailed account of what investigators think happened to 17-year-old Brittanee Drexel of Rochester, New York, after she disappeared in 2009 whole on a spring break trip. His account, contained in a federal court transcript obtained by The Post and Courier of Charleston, is based on a statement from a prison inmate who claims he was present when she was killed.

But a McClellanville woman whose husband and son have been implicated by the inmate says the story is just a bunch of “craziness” adopted by federal authorities desperate to solve the case.

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In the transcript, Munoz testifies that the inmate, Taquan Brown of Walterboro, told investigators he went to a “stash house” in the McClellanville area in the days after Drexel was abducted​. As he entered the house with a couple of other men, he saw Timothy Da’Shaun Taylor, then 16, “sexually abusing Brittanee Drexel,” the agent said.

Munoz said Brown said he saw others also in the room with the girl and Da’Shaun Taylor, and he kept walking through the house to the backyard to give some money to Da’Shaun Taylor’s father, Shaun Taylor. As the two talked, Drexel ran from the house. She was “pistol-whipped” and taken back inside.

According to Brown’s account, two shots rang out and the inmate assumed Shaun Taylor shot the girl. Then the girl’s body was wrapped up and taken away.

Asked what happened to the girl’s body, Munoz testified that it has not been found but that “several witnesses have told us Miss Drexel’s body was placed in a pit, or gator pit, to have her body disposed of. Eaten by the gators.”

Munoz told the court that investigators have searched several alligator ponds to no avail. He said investigators have been told that the area has as many as 40 such ponds. Investigators also have searched the stash house, the agent testified.

The FBI agent’s testimony came out during a bond hearing on an unusual charge against Da’Shaun Taylor that his attorney, David Aylor, characterized in the transcript as “clearly nothing but a squeeze-job” designed to pressure him into confessing and helping the government.

Taylor’s mother, Joan Taylor, 44, of McClellanville, told The Post and Courier on Thursday that she’s talking out about the accusations because she believes the government is unjustly trying to “pin something else on him” based on a bogus jailhouse confession.