Foreign and Commonwealth Office says visitors should not hand documents to Israeli officials unless absolutely necessary

Britons travelling to Israel are warned not to hand their passports over to Israeli officials unless it is absolutely necessary in travel advice issued by the Foreign and Commonwealth Office.

The advice, posted on the FCO website yesterday, serves to underline the government's anger and grave concern over the forged passports controversy.

The advisory was issued on the back of information from the Serious Organised Crime Agency. FCO officials admitted such a step was not usual but said it had a "duty" to protect British citizens whose lives might be endangered.

It follows Britain's belief that passports were copied by Israel at Ben Gurion airport.

But it is likely to cause alarm and confusion among the 150,000 Britons who visit Israel annually.

The updated advice reads: "UK passport holders should be aware of a recent Serious Organised Crime Agency investigation into the misuse of UK passports in the murder of Mahmud al-Mabhuh in Dubai on 19 January 2010.

"The Soca investigation found circumstantial evidence of Israeli involvement in the fraudulent use of British passports. This has raised the possibility that your passport details could be captured for improper uses while your passport is out of your control. "The risk applies in particular to passports without biometric security features. We recommend that you only hand your passport over to third parties including Israeli officials when absolutely necessary."

A Foreign and Commonwealth Office spokesman said: "Generally our advice, wherever you are travelling, would be pretty standard that you should be careful about your own personal documents in all circumstances and not part with personal data.

"Obviously, our advice is in reaction to the current issues. We have included it because the way that British passports were cloned and used has endangered British lives, and we have a duty to inform British nationals when we are aware of significant potential threats to their safety.

"It is a warning based on the Soca conclusions. Obviously this situation is about cloning passports. Travel advice needs to be targeted to make people aware of general issues and also of specific issues."