Memri, the "research institute" which specialises in translating portions of the Arabic media into English, has issued a video clip from a children's programme on Hamas TV in which it claims that a Palestinian girl talked of becoming a suicide bomber and annihilating the Jews.

Memri - described by New York Times columnist Thomas Friedman as "invaluable" - supplies translations free of charge to journalists, politicians and others, particularly in the US.

Though Memri claims to be "independent" and maintains that it does not "advocate causes or take sides", it is run by Yigal Carmon, a former colonel in Israeli military intelligence. Carmon's partner in setting up Memri was Meyrav Wurmser who in 1996 was one of the authors of the now-infamous "Clean Break" document which proposed reshaping Israel's "strategic environment" in the Middle East, starting with the overthrow of Saddam Hussein.

In the Hamas video clip issued by Memri, a Mickey Mouse lookalike asks a young girl what she will do "for the sake of al-Aqsa". Apparently trying to prompt an answer, the mouse makes a rifle-firing gesture and says "I'll shoot".

The child says: "I'm going to draw a picture."

Memri's translation ignores this remark and instead quotes the child (wrongly) as saying: "I'll shoot."

Pressed further by the mouse - "What are we going to do?" - the girl replies in Arabic: "Bidna nqawim." The normal translation of this would be "We're going to [or want to] resist" but Memri's translation puts a more aggressive spin on it: "We want to fight."

The mouse continues: "What then?"

According to Memri, the child replies: "We will annihilate the Jews."

The sound quality on the clip is not very good, but I have listened to it several times (as have a number of native Arabic speakers) and we can hear no word that might correspond to "annihilate".

What the girl seems to say is: "Bitokhoona al-yahood" - "The Jews will shoot us" or "The Jews are shooting us."

This is followed by further prompting - "We are going to defend al-Aqsa with our souls and blood, or are we not?"

Again, the girl's reply is not very clear, but it's either: "I'll become a martyr" or "We'll become martyrs."

In the context of the conversation, and in line with normal Arab-Islamic usage, martyrdom could simply mean being killed by the Israelis' shooting. However, Memri's translation of the sentence - "I will commit martyrdom" turns it into a deliberate act on the girl's part, and Colonel Carmon has since claimed that it refers to suicide bombers.

The overall effect of this is to change a conversation about resistance and sacrifice into a picture of unprovoked and seemingly motiveless aggression on the part of the Palestinians. But why hype the content in this way? Hamas's use of children's TV for propaganda purposes is clearly despicable, as the BBC, the Guardian and others have noted, without any need to exaggerate its content.

Among those misled by Memri's "translation" was Glenn Beck of CNN, who had planned to run it on his radio programme, until his producer told him to stop. Beck informed listeners this was because CNN's Arabic department had found "massive problems" with it.

Instead of broadcasting the tape, Beck then invited Carmon on to the programme and gave him a platform to denounce CNN's Arabic department, and in particular to accuse one of its staff, Octavia Nasr, of being ignorant about the language.

Carmon related a phone conversation he had had with Ms Nasr:

She said the sentence where it says [in Memri's translation] "We are going to ... we will annihilate the Jews", she said: "Well, our translators hear something else. They hear 'The Jews are shooting at us'." I said to her: "You know, Octavia, the order of the words as you put it is upside down. You can't even get the order of the words right. Even someone who doesn't know Arabic would listen to the tape and would hear the word 'Jews' is at the end, and also it means it is something to be done to the Jews, not by the Jews." And she insisted, no the word is in the beginning. I said: "Octavia, you just don't get it. It is at the end" ... She didn't know one from two, I mean.

Carmon's words succeeded in bamboozling Glenn "Israel shares my values" Beck, who told him: "This is amazing to me ... I appreciate all of your efforts. I appreciate what you do at Memri, it is important work."

It was indeed amazing, because in defending Memri's translation, Carmon took issue not only with CNN's Arabic department but also with all the Arabic grammar books. The word order in a typical Arabic sentence is not the same as in English: the verb comes first and so a sentence in Arabic which literally says "Are shooting at us the Jews" means "The Jews are shooting at us".

I have written about Memri's tweaking of translations before. One example was its manipulation of Osama bin Laden's speech on the eve of the last American presidential election (details here, at the end of the article). Another was an Egyptian newspaper's interview with the mufti of Jerusalem. Memri's translators changed the question: "How do you deal with the Jews who are besieging al-Aqsa and are scattered around it?" to "How do you feel about the Jews?" They then heavily edited the mufti's words to give an anti-semitic-sounding reply to the new question.

The curious thing about all this is that Memri's translations are usually accurate (though it is highly selective in what it chooses to translate and often removes things from their original context). When errors do occur, it's difficult to attribute them to incompetence or accidental lapses. As in the case of the children's TV programme, there appears to be a political motive.

The effect of this is to devalue everything Memri translates - good and bad alike. Responsible news organisations can't rely on anything it says without going back and checking its translations against the original Arabic.