VATICAN CITY: Pope Francis today criticised church leaders who "defamed" and "dragged through the mud" the controversial Salvadoran archbishop Oscar Romero before and after his assassination.

The archbishop was shot dead in 1980 by an extreme right-wing commando -- largely because the church leader adamantly defended poor farmers evicted from their land.

Romero was beatified in May after a ceremony that was stalled for decades because conservatives within the Church found him too left-leaning. It was Argentinian Pope Francis, the first-ever Latin American pope, who finally gave the green light for the beatification.

Francis, who received a delegation from the Salvadoran church today, condemned those who attacked the archbishop.

The pontiff said that Romero's martyrdom began before his death because of the persecution he faced, and continued after he was killed.

"His martyrdom also continued after he died, because it was not enough that he was dead," Francis said.

"He was defamed, slandered, dragged through the mud."

Called the "Voice of the Voiceless" because of his fervent fight for the poor, Romero was also called "imbalanced" and a "Marxist" by some Latin American critics.

After the long road to beatification, Romero, who left a powerful leftist legacy in Latin America, is one step closer to being declared a saint more than 35 years after his death.