Expelled ANC Youth League leader Julius Malema was a "dangerous fellow", the National Union of Mineworkers (NUM) said on Friday.
Malema has never worked anywhere in his life and has failed to unite the ANCYL, said deputy president Piet Matosa.
"He only wants to see people suffering and without jobs... hence we continue to warn miners against this dangerous fellow."
Malema has been visiting miners since the Lonmin Marikana strike commenced last month.
Last week, he told striking miners at Goldfields near Carletonville not go back to work until their demands were met.
He also called on a national strike to take place once a week every month.
Matosa said Malema did not contribute a cent to starving Aurora mineworkers who went for months without receiving their wages.
"Instead, he decided to demolish a R3-million house and build an R18-million mansion during that time. He is not a good leader."
He said NUM was getting close to finding out who funded Malema.
"Malema can't be pulling this by himself. He is too young for that... we are getting close to finding out who his funders are."