Israel is apparently backing away from an allegation that a Canadian surgeon and two Norwegians working in southern Lebanon were suspected members of a European terrorist organization.
Instead, the Israeli Embassy is now saying that the three were detained and questioned by the Israeli armed forces during the fighting in southern Lebanon because they worked with the Palestinian Red Crescent Society, an organization considered to be part of the ''terrorist'' Palestine Liberation Organization (PLO).
The three - Christopher Giannou of Canada and Steinar Berge and Oyvind Moller of Norway - all said following their release that they had seen Israeli soldiers beat prisoners. Berge is a physician and Moller a child care worker.
In response to queries about the allegations from the three, an Israeli Embassy spokesman, Nachman Shai, told the New York Times that all three had ties to a European terrorist organization. He declined to identify publicly the group with which the three were supposedly associated. The Canadian and Norwegian governments subsequently issued strong statements saying the Israeli charge was without foundation. Both governments pressed the Israeli Foreign Ministry for an explanation, but embassies of the two governments here say that the Israelis never responded either with evidence or further allegations.
Marc Lortie, a Canadian press spokesman, said that Israeli Foreign Ministry officials at one point told his government that Mr. Shai's statement had been based on ''press reports.'' It was not clear to the Canadian spokesman what press reports were being referred to, but he assumed the reference was to unspecified Israeli press reports.
Mr. Shai is currently on vacation. Another Israeli Embassy spokesman, Benjamin Abileah, makes it sound as though the Israelis have changed their tune on the reason for detaining the Canadian and Norwegians.
Mr. Abileah said that the Israelis detained the three ''on suspicion that they were involved with the PLO.''
''They were in the service of the Palestinian Red Crescent,'' Mr. Abileah said. ''This was very much sufficient grounds to look into the background of these people.
''There was no doubt that they were ideologically committed,'' he said. ''The Red Crescent is an arm of the PLO and is headed by the blood brother of Yasser Arafat.''
In interviews, however, none of the three ever made any secret of their association with the Palestinian Red Crescent or of their sympathy for the PLO. But they strongly objected to being called members of a European terrorist organization. Asked about Mr. Shai's allegation to this effect, Mr. Abileah said: ''What I would have said, to be on the safe side, is that Dr. Giannou was working with an arm of the PLO. . . .''
The Israeli spokesman said that the account by Dr. Giannou and the two Norwegians of what they had seen while being held by the Israelis contained ''a lot of inaccuracies - and inaccuracy is a soft word for it. The things they told of never happened, like the beating of prisoners, like bodies being carried out.''
Mr. Abileah said that his conclusions were based largely on information provided by Israeli military officers on the scene in southern Lebanon.