An analysis of SNIa events in early type galaxies from the Cappellaro et al (1999) database provides conclusive evidence that the rate of type Ia Supernovae (SNe) in radio-loud galaxies is about 4 times higher than the rate measured in radio-quiet galaxies, i.e. SNIa-rate(radio-loud galaxies) = 0.43^+0.19_-0.14h^2_75 SNu as compared to SNIa-rate(radio-quiet galaxies) = 0.11^+0.06_-0.03h^2_75 SNu. The actual value of the enhancement is likely to be in the range ∼ 2-7 (P∼ 10^-4). This finding

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... on robust empirical grounds the results obtained by Della Valle & Panagia (2003) on the basis of a smaller sample of SNe. We analyse the possible causes of this result and conclude that the enhancement of SNIa explosion rate in radio-loud galaxies has the same origin as their being strong radio sources, but there is no causality link between the two phenomena. We argue that repeated episodes of interaction and/or mergers of early type galaxies with dwarf companions, on times-scale of about 1 Gyr, are responsible for inducing both strong radio activity observed in ∼14 supply an adequate number of SNIa progenitors to the stellar population of ellipticals.