Primero Announces Legal Claim Filed by Mexican Tax Authorities

Primero Mining Corp.

announced today that its Mexican subsidiary, Primero Empresa Minera, S.A. de C.V. ("PEM"), has received a legal claim from the Mexican tax authorities, Servicio de Administración Tributaria ("SAT"), seeking to nullify the Advance Pricing Agreement ("APA") issued by SAT in 2012. The APA confirmed the Company's basis for paying taxes on realized silver prices for the years 2010 to 2014 and represented SAT's agreement to accept that basis for those years. The legal claim initiated does not identify any different basis for paying taxes. The Company believes this legal claim is without merit and it intends to vigorously defend the validity of its APA. The Company's operations continue as usual.PEM and its legal counsel are in the process of completing a detailed review of the legal claim, which is in excess of 200 pages. The Company's Mexican legal and financial advisors have informed the Company that SAT's judicial challenge to the validity of an APA is without precedent. The Company's advisors maintain that seeking to nullify an APA undermines the function of an APA, which is to assure a taxpayer