  As part of a survey for radio pulsars with the Parkes 64-m telescope we have
discovered PSR J1622-4950, a pulsar with a 4.3-s rotation period. Follow-up
observations show that the pulsar has the highest inferred surface magnetic
field of the known radio pulsars (B ~ 3e14 G), exhibits significant timing
noise and appears to have an inverted spectrum. Unlike the vast majority of the
known pulsar population, PSR J1622-4950 appears to switch off for many hundreds
of days and even in its on-state exhibits extreme variability in its flux
density. Furthermore, the integrated pulse profile changes shape with epoch.
All of these properties are remarkably similar to the only two magnetars
previously known to emit radio pulsations. The position of PSR J1622-4950 is
coincident with an X-ray source that, unlike the other radio pulsating
magnetars, was found to be in quiescence. We conclude that our newly discovered
pulsar is a magnetar - the first to be discovered via its radio emission.
