The accusation - implying that a man who was in every Italian government from 1946 to 1992 was in effect pulling Mafia strings - is a serious one, even when levelled against someone whose copybook is already indelibly blotted.
Mr Andreotti is on trial in Perugia for allegedly ordering the murder in 1979 of the muck- raking journalist Mino Pecorelli. He is also in the dock in Sicily for his supposed Mafia links, in a case constructed around dramatic evidence against him from pentiti, as mafiosi who turn state's evidence are known. But though they started out with what seemed like a water-tight case, prosecutors have seen wide cracks appearing in that construction as evidence from pentiti dried up or was proved false.
Now B rusca is wading in, including Mr Andreotti in the constant stream of damning accusations that he has come up with since his arrest in 1996. But prosecutors are unlikely to rejoice over his version of events.
The extreme haste with which Brusca, reputed to be a brutal Mafia killer, insisted on turning his back on the mob immediately after his arrest has marred his evidence, endowing it with an air of insincerity. Moreover, his clever knack of producing testimony which never nails anyone in the world of organised crime has not endeared him to investigators.
It has, however, made him popular with the growing chorus of mainly right- wing MPs who believe that pentiti should be taken with a large pinch of salt. Yesterday Brusca told the court that he had turned state's evidence "for my son. I don't want him to go the same way I did."
But this paternal concern did not extend to the family of pentito Santo Di Matteo: Brusca is accused of having strangled Di Matteo's 11-year-old son and then having had the body dissolved in acid to punish Santo for ratting on the mob.
Di Matteo is one of the few pentiti whose testimony is rarely questioned. Yet in a courtroom in Caltanissetta, Sicily, yesterday he said would give no more evidence; the state protection being offered him against his former Mafia colleagues was inadequate, he said.