Sixty-four-year-old Herrera voluntarily appeared at the offices of prosecutors in the capital Bogota, AFP reporters witnessed.

He was to be questioned about allegations by two former paramilitaries that in 2002 he conspired to kill four of his neighbours in central Colombia.

The two ex-paramilitaries – members of one of the bloody far-right death squads that for decades fought Colombia left-wing guerrillas – claim “Lucho” gave them about US$9,700 to murder four men.

They alleged that Herrera claimed the men were rebels who wanted to kidnap him, but were in fact farmers who had refused to sell their land.

Lawyer Hernando Benavides said his client Herrera was innocent and a “victim of events of which he is unaware”.

One of the paramilitaries was recently sentenced to more than 22 years in prison over the forced disappearance of the men.

A source from the prosecutor’s office told AFP that Herrera had been invited to provide his “free version” of events, and was not obliged to attend as he is not listed as a defendant.

Herrera has publicly denied belonging to criminal organisations or purposely causing anyone harm.

But he could yet face formal charges.

His brother Rafael Herrera was also requested to be present yesterday.