The Russian Finance Ministry has reportedly tightened its proposed penalties for the issuance of so-called money surrogates including digital currencies.

News service Interfax has reported that, according to an unnamed source in the Russian government, individuals who issue money surrogates face as many as four years in prison. Executives with financial firms that release their own money surrogates could be imprisoned for as many as seven years and be restricted from holding similar positions in the future.

Fines for issuing a money surrogate, according to Interfax, range from 500,000 rubles to 1 million rubles, or roughly $7,000 to $14,000, respectively. Executives from financial firms could pay as much as 2.5 million rubles, or about $35,000.

The report comes as Russia moves closer to formally weighing legislation that, if passed, would govern activities involving money surrogates, a classification of non-government issued currencies that includes bitcoin and other digital currencies. Efforts to formalize restrictions on money surrogates began in 2014.

In February, an advisor to Russian President Vladimir Putin issued public statements suggesting that the acceptance of bitcoin would be considered a criminal act.