VALLETTA: Daphne Caruana Galizia, a prominent Maltese blogger who accused the island's centre-left government of corruption, was killed by a car bomb on Monday, Prime Minister Joseph Muscat announced.

Speaking at a press conference, Muscat condemned the killing as a "barbaric" act and ordered security services to devote maximum resources to bringing those responsible to justice.

"What happened today is unacceptable on various levels. Today is a black day for our democracy and our freedom of speech," he said.

"I will not rest until justice is done."

Caruana Galizia's death comes four months after Muscat's Labour Party won a resounding victory in a general election he called early as a result of a series of scandals engulfing his inner circle, to which Caruana Galizia's allegations were central.

Muscat, who has been premier since 2013, went to the polls a year early after his wife was implicated in one of a series of alleged corruption cases arising from the so-called Panama Papers data leak.

He has always denied any wrongdoing and promised to quit if any evidence emerges of his family having secret offshore bank accounts used to stash kickbacks — as Caruana Galizia had alleged.

The blogger had a record of correctly highlighting previous scandals in the island nation. — AFP