The mother of Muhammad Musallam, weeps as she holds his photograph, Feb. 12

DAMASCUS — “Islamic State” said on Thursday it was holding an Israeli Arab who had posed as a foreign fighter in order to spy for Mossad, an account denied by Israel and by the man’s family, who said he had been kidnapped.

In an interview published by IS online English-language magazine Dabiq, Muhammad Musallam, 19, said he had joined the insurgent group in Syria so as to report to the Israelis on its weapons caches, bases and Palestinian recruits.

After his conduct aroused the suspicion of “Islamic State” commanders, Musallam was quoted as saying, he broke cover by phoning his father in East Jerusalem, leading to his capture.

“I say to all those who want to spy on the “Islamic State,” don’t think that you’re so smart and that you can deceive the Islamic State. You won’t succeed at all,” he said, according to Dabiq.

“Stay away from this path. Stay away from helping the Jews and the murtaddin (apostates). Follow the right path.”

Musallam’s father, Sai’d, denied his son was a spy, saying he went missing after traveling as a tourist to Turkey. Muhammad then phoned home, saying he had been abducted to neighboring Syria but could buy his way out, his father said.

“He said, ‘Dad, I need $200 or $300 so they will let me go,'” Said Musallam told Reuters. Before he could send the money, he said, another man phoned to inform him Muhammad had escaped his captors but had been seized by “Islamic State.”

An Israeli security official said Musallam traveled to Turkey on Oct. 24 in order to fight for “Islamic State” in Syria.

“He went on his own initiative, without his family’s knowledge,” the official told Reuters. Asked whether his statement constituted a denial that Musallam was an Israeli spy, the official said: “You can understand it that way, yes.”