An attempt to prosecute Cliven Bundy for leading an armed standoff against the federal government has ended in a mistrial, the latest setback for government efforts to penalise the Bundy family and its followers.

US District Judge Gloria Navarro said prosecutors had committed “constitutional due-process violations” and faulted them for not turning over evidence to defence attorneys, according to the Associated Press.

The trial concerned a confrontation outside the Bundy family ranch in Nevada, where a dispute over more than $1m in unpaid grazing fees turned into an armed standoff that drew in scores of supportive militiamen after the government began rounding up cattle under a court order.

“We are a step closer to freedom,” Carol Bundy, whose husband Cliven and sons Ammon and Ryan have faced federal charges, wrote on Facebook.

The Nevada clash, and a subsequent takeover of an Oregon wildlife refuge by people aligned with the Bundys, became magnets for people angry about perceived government overreach in the American West. Much of the land west of the Rocky Mountains is managed by the federal Bureau of Land Management, and Cliven Bundy — the family’s patriarch — asserted that the government lacked the constitutional authority to oversee the land where his cattle fed.

So far, prosecutors have a mixed record on winning convictions against participants in the two insurrections.

Protest against the occupation of the Malheur National Wildlife Refuge Show all 5 1 /5 Protest against the occupation of the Malheur National Wildlife Refuge Protest against the occupation of the Malheur National Wildlife Refuge Protesters hold signs during a rally against the occupation of the Malheur National Wildlife Refuge by Ammon Bundy and his armed followers, while at the Federal Building in Eugene AP Protest against the occupation of the Malheur National Wildlife Refuge With the armed takeover of the national wildlife refuge in southeastern Oregon in its third week, Bundy and his armed group are still trying to muster up broad community support, so far without much luck AP Protest against the occupation of the Malheur National Wildlife Refuge Protesters rally against the occupation of the Malheur National Wildlife Refuge by Ammon Bundy and his armed followers, while at the Federal Building in Eugene AP Protest against the occupation of the Malheur National Wildlife Refuge John Perry holds a poster during a rally against the occupation of the Malheur National Wildlife Refuge by Ammon Bundy and his armed followers AP Protest against the occupation of the Malheur National Wildlife Refuge Renee Irvin holds a sign during a rally against the occupation of the Malheur National Wildlife Refuge AP

In April, jurors deadlocked on charges against six men accused of threatening government agents during the Bundy ranch standoff. In August, a federal jury did not return guilty verdicts against four men facing conspiracy and weapons charges.