A FORMER Mafia boss who once ordered executions on suspected mob turncoats has made gangland history with his own betrayal, becoming the highest-ranking member of New York’s five Italian organised crime families to testify against one of his own.

Jailed don Joseph Massino secretly recorded his successor plotting the assassination of a federal prosecutor, becoming the first head of a New York Mafia family known to have turned government informant, sources familiar with the case said.