Raggi stands by Rome environment councillor under investigation.

Rome's beleaguered mayor Virginia Raggi says she stands by her environment councillor Paola Muraro who is currently under investigation relating to her former role as consultant for the city's refuse collection company AMA Roma.

Raggi, of the anti-establishment Movimento 5 Stelle (M5S), at first repeatedly denied knowing about the criminal investigation before admitting in recent days that she has been aware of the probe since July.

The revelation has proved deeply damaging for the M5S which swept to victory in Rome with pledges of transparency and anti-corruption policies.

Raggi, whose administration was recently rocked by five key resignations in one day, is under increasing attack from the opposition, including Italian premier and Partito Democratico (PD) secretary Matteo Renzi, who said he had "never seen so many lies one after the other."

Accusing the opposition of a smear campaign, the M5S has promised to emerge from the scandal stronger than before, while its leader Beppe Grillo said Raggi's “difficult position” was comparable to "the first black mayor in Mississippi in 1968."