In this Monday, Feb. 3, 2014 photo provided by the Marshall Islands Foreign Affairs Department, a man identifying himself as 37-year-old Jose Salvador Alvarenga sits on a couch in Majuro in the Marshall Islands, after he was rescued from being washed ashore on the tiny atoll of Ebon in the Pacific Ocean.
Majuro, Marshall Islands (CNN) -- The mysterious castaway who turned up in the Marshall Islands after saying he spent 13 months at sea has been moved to an undisclosed location to avoid the media, sources familiar with his care told CNN on Saturday.
Security around Jose Salvador Alvarenga has tightened since he came ashore last week more than 6,600 miles from where he says he started; a crush of media has descended on the tiny island nation.
Alvarenga, a Salvadoran who lived and worked in Mexico, was moved overnight from the Marshall Islands Resort Hotel in Majuro, the sources said.
Security continues to guard the room where Alvarenga was staying at the resort, giving the impression he is still there, according to the sources.
His return journey to El Salvador this week was postponed because of his health, but Dr. Kennar Briand, chief of staff at Majuro Hospital in the Marshall Islands, says Alvarenga is ready to travel.
The castaway will have another medical checkup on Monday to see whether he is fit to return home, Briand said.
Alvarenga's mental health appears to have improved, too, the doctor said.
"He was a bit 'off,' maybe it's due to him being in the open for so many months and not talking to people, but I think he is finally getting it back," Briand said.
Alvarenga was released from the hospital in Majuro on Friday, one day after being readmitted because of declining health.
Alvarenga's claims have garnered widespread skepticism about how he could survive for 13 months adrift in the Pacific. But from what officials can tell, they have no reason to doubt him.
CNN's Chelsea J. Carter contributed to this report.