Radu was, according to Ion Mihai Pacepa, a radiological weapon used against dissenters and critics by Nicolae Ceaușescu's Securitate. "Radu" is a Romanian name and in this context it is a reference to "radiation". The weapon was intended to lead to cancer which would result in death within months after the exposure.
According to Pacepa, it was created by the Securitate's "Service K" in spring 1970, using radioactive materials it received from the KGB. The Romanian "Service K", founded in 1950s by the Soviets using the KGB model, was in charge of the dirty work against jailed prisoners who they considered dangerous to the regime. This included monitoring them with microphones and trying to frame them by inducing them into making incriminating statements. The service was also in charge of killing them and making it appear like a suicide or natural death.
Historian Mihai Pelin claimed in a book on Radio Free Europe, Melița și Eterul, that there was no such weapon, but others, such as RFE journalist Nestor Ratesh, argue that Pelin also claimed the Securitate was not involved in the RFE bombing, but eventually it turned out that they were the ones who hired Carlos the Jackal for this job.
Critics of Ceaușescu who died of cancer and are suspected to have been irradiated by the Securitate include: