The classified 15-page note from the French military intelligence service, published in April by new investigative media outlet Disclose, details the use of weapons - including tanks, artillery and military ships - in the war against Huthi rebels.
It concluded that the UAE and Saudi Arabia had deployed French weaponry.
The Paris government has always insisted that the arms are only used in defensive circumstances to deter attacks by the Huthis.
"The confidential documents revealed by Disclose and its partners are of major public interest, that bring to the attention of citizens and their representatives what the government wanted to conceal," said an editorial for Disclose and its partners.
Disclose worked with several media organisations including public broadcaster France Info, online brand Mediapart and Franco-German television channel Arte.
The founder of Disclose, Geoffrey Livolsi, told AFP that at least three journalists who took part in the investigation have been called in for a hearing conducted by France's domestic intelligence agency, the DGSI, next month.
"This judicial investigation has only one objective: to know the sources that allowed us to do our job. It is an attack on the freedom of the press and the protection of the sources of journalists," Livolsi said.
The investigation into the "compromise of national defence secrecy" was launched by prosecutors on December 13 last year after a complaint by the armed forces ministry, a judicial source said.
French Armed Forces Minister Francoise Parly said during an interview in January on France Inter public radio: "I'm not aware that any (French) arms are being used in this conflict."