A reclusive billionaire, anti-tax crusader and major financial backer of Donald Trump has been named as the anonymous private donor who gave $130m to the government to help pay US troops during the federal shutdown that is now in its fourth week, according to the New York Times.

The donation, which equates to about $100 per service member, appears to be a potential violation of the Antideficiency Act, which prohibits federal agencies from spending funds in advance or in excess of congressional appropriations – and from accepting voluntary services “except in the case of emergency involving the safety of human life or the protection of property”.

Potential penalties for violations include both administrative and criminal sanctions such as suspension or removal from duty, fines and imprisonment.