Israel's internal security agency has been authorised to demand "suspicious" foreign travellers open their personal email accounts for inspection on entry to the country.

Shin Bet officials have been given approval for such action in what they deem to be exceptional cases by Israel's attorney-general, Yehuda Weinstein, despite a petition to overrule the measure by a leading civil rights group.

"The threat of using foreign citizens for terrorist purposes is a growing trend," said Nadim Avod, a lawyer in the attorney-general's office. "Searching an email account is to be carried out in exceptional cases only after suspicious or pertinent information has been identified."