Caruso has been charged with aggravated burglary and summary charges of common assault and unlawful trespass as a result of an alleged incident.
The incident occurred while Caruso was assisting a friend in enforcing an abandonment order and a subsequent property seizure and delivery order at that friend's premises.
Caruso advised the company that he considered himself to be acting with lawful authority and in accordance with all relevant laws and that accordingly, the charges would be vigorously defended.
The company said Caruso had retained an eminent senior counsel.
Caruso has elected to step down as a director of the company whilst he defends the charges, but will continue in his role as chief executive officer.
"The board has confidence that he will continue to perform his duties in the best interests of the company," MRC said.
MRC director David Baker has been appointed as independent non-executive chairman.
Caruso has been a director of MRC since 2000 and has been CEO and executive director since 2012.
"As this matter is before the courts, the company will not make any further comment until the matter has been finalised," MRC said.
MRC shares were unchanged at A32c in early trade, valuing the company at about $145 million.
MRC produces mineral sands via its Tormin mine in South Africa, and also has advanced graphite projects in Norway.
Caruso has also resigned as chairman of Connexion Telematics.