A third British national was wounded in the attack, which reportedly took place on Monday (26 March) in the town of Darkoush near the Turkish border.
Spanish newspaper El Mundo has named the two killed, based on reports by the Local Coordination Committees in Syria. The wounded journalist has not been named.
El Mundo adds that none of the information has been independently verified due to restrictions imposed on journalists in the country. The CPJ says it has interviewed a witness who also confirmed the identities.
The report by the press freedom group says that the freelancers were believed to have been filming a documentary in the country when "the Syrian army, along with plainclothes militiamen known as 'Shabiha', began shooting at the home Monday morning, according to the witness interviewed by CPJ".
The Guardian yesterday reported that the men, thought to be in their twenties or thirties were initially thought to be Algerian. The report states that Sarah Giaziri from the Rory Peck Trust, which supports freelance newsgatherers, "said a Syrian fixer told her the two men were in fact British nationals, although this can not be confirmed at present".
"There was another man with them, also reportedly a British national of Algerian origin who is reportedly in hospital in Antakya."
A spokesperson for the Foreign Office told Journalism.co.uk that they are "aware of the reports and looking into them", adding that "it takes longer to look into such reports" due to not having representation on the ground in Syria.
The spokesperson added that anyone travelling to Syria at present is doing so against FCO advice.
Ten journalists have been killed in Syria since November, making it the most dangerous place for journalists in the world, CPJ research shows.