NEW DELHI: Even as officials probing the Monday's attack on the wife of an Israeli diplomat in the national Capital are largely focusing on foreign students, evidence shows that certificates submitted by students from some of the Asian countries are inconsistent. Sources said that they suspect that some of the certificates could be bogus. Investigators have been going through the details of visitors from these countries who have entered India in recent weeks. Immigration details are being closely studied to figure out antecedents of those who entered India ahead of the attack from countries like Iran, Syria etc, sources said. Students from other west Asian nations are also under the lens. Officials said they have interviewed over 50 students since the attack to gauge their movements and affiliations. Many of these students have affiliations to organizations such as Hizb ut-Tahrir that has radical views on Israel. Investigators are working on a theory that the attacker was a young man with intimate knowledge of the national Capital. Since the attack seems linked to the Israel-Iran stand-off, the possibility of a foreigner, probably a student, carrying out the act cannot be ruled out, they believe. Even as police and intelligence officials verify foreign students here for `links' to the attack, sources are pointing fingers at what they call are "inconsistencies" in the documentation of several foreign students. This is stark in the case of students from countries such as Afghanistan, they said. India extends special scholarships to students from some of the countries, but many come on their own too. The scholarships are administered by the Indian Council for Cultural Relations. "Many of the certificates of students from the same country and from the same board do not seem to be consistent. There are tell-tale differences in these certificates, which raise questions," one source, who has handled several of these certificates, said. A senior official in the security establishment said he has also been told of "bogus" admissions. "It is something that needs to be probed separately," he said, but did not specify if they are carrying out a separate drive to scrutinize the documents of foreign students from some of west Asian countries.