Israel's former head of military intelligence was questioned by UK immigration officers when he landed at Heathrow airport.
Amos Yadlin, a director of the Institute for National Security Studies, said he was detained for 10 minutes.
Mr Yadlin was on an INSS delegation to London last week with former Israel Defence Forces chiefs Gabi Ashkenazi and Dan Halutz and former minister Gideon Saar and Yaakov Amidror, Israel's former National Security Advisor.
Israeli media speculated that the delegation was questioned in connection with war crimes charges brought in international courts. But the JC understands that the Home Office does not have any specific guidance on the questioning of Israeli military personnel.
Mr Yadlin told Israeli TV's Channel 2: "Everyone passed through passport control, but they delayed me for 10 minutes. They probably had something on their computer they wanted to check."