South African right-winger and former Rhodesian SAS soldier Willem Ratte and 10 others were arrested for possession of illegal firearms, Mpumalanga police say.
Police arrested the men on a farm in Balmoral near Witbank on Thursday afternoon.
"We don't have much information at this stage. The 11 were arrested for being in possession of unlawful firearms and ammunition," police spokesman Captain Leonard Hlathi said.
They also allegedly had a number of different uniforms in their possession, he said.
The men were expected to appear in the Witbank Magistrate's Court on Monday.
In 2001 Ratte was found guilty of sabotage in relation to a 1997 break in at the Pomfret military base in the Northern Cape.
He was convicted of sabotage and spent four years in jail.
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