Dali Mpofu will launch an application to have Mr X testify in person at the Marikana commission.
The NUM has slammed Lonmin's decision to grant rival union Amcu majority recognition.
Police raided hostels ahead of Friday's anniversary of the Marikana tragedy last year.
A female shop steward affiliated with the NUM has been shot dead outside the mine’s Rowland shaft.
It is alleged that NUM shop stewards fraudulently changed the union membership of about 200 miners.
One man was killed and another wounded in a shooting on Monday.