A former TWA hostage said Friday he received a mysterious telephone call from Beirut about a month before testifying at the trial of confessed hijacker Mohammed Ali Hamadi.

Ralf Traugott, who was aboard the plane hijacked in 1985, also described how the Shiite Moslem calmly said, "This is the man we killed," after he read an article about the American Navy diver slain aboard the TWA jetliner.Traugott, 36, a German-born American citizen, said he received a telephone call about four weeks ago in which a man identified himself as "Mr. Hamadi" and said he was calling from Beirut.

"I thought it was kind of strange," Traugott said. "The man on the other end of the line said, `Hello Mr. Ralf.' "

"I said, `Who's this?' and he said, `Mr. Hamadi. This is Beirut, Lebanon calling,' " Traugott said. The man then hung up, he said.

Hamadi comes from a family of 11 children. One of his brothers, Abdul-Hadi, is the security chief for Hezbollah, or Party of God, a radical Shiite Moslem group backed by Iran and believed to be holding the foreign hostages in Lebanon.

Hamadi has denied being a member of Hezbollah, but has admitted to taking part in the hijacking of TWA Flight 847, which was seized on an Athens-to-Rome flight and diverted to Beirut and Algiers. Thirty-nine Americans were held hostage for 17 days and U.S. Navy diver Robert Stethem, 23, of Waldorf, Md., was shot and thrown out of the plane to die on the tarmac at Beirut airport.

Hamadi is charged with murder and air piracy.

Traugott showed the court a Lebanese newspaper, An-Nahar, dated June 16, 1985.

The newspaper included photographs of the hijacked plane and of Stethem's body on the tarmac. Traugott said Hamadi had been reading the newspaper aboard the plane.

"I asked him what was in it," Traugott said. "He said, `This is the man we killed.' I asked him, `Did you shoot him?' "

"He said, `No, my friend shot him,' " Traugott said. "He said it very nonchalantly, like it was no big deal."

Court documents have identified Hamadi's accomplice as Hassan Ezzeddine, who is at large.