Does the name of an informant need to be disclosed to a magistrate in connection with a search warrant?

While the name of an informant need not be disclosed [240 Cal.App.2d 506] to a magistrate in connection with an application for a search warrant, unless the magistrate requests it, ⁴ it is, of course, now well settled that, where an officer relies on data from an informant to show probable cause for a non-warrant arrest, the name of the informant must, on timely demand, be disclosed, on penalty of having the informant's data stricken and disregarded. (Priestly v. Superior Court (1958) 50 Cal.2d 812, 330 P.2d 39.) Here, defendant duly demanded the name of the informant at the preliminary examination and the demand was peremptorily refused; the point was followed up by a motion to strike, made in the superior court. At no stage of the proceedings was the name of the informant divulged. For lack of disclosure, the informant's data cannot be relied on to show probable cause. As we said above, without that data, the other information was insufficient.