As unlikely spies go, a master furrier, head of the West End ladies' fur coat company, Swears and Wells, would be hard to beat.

But according to secret intelligence reports just released by the National Archives, Cyril Ross was just that.

As Israel fought for its existence in May 1948,leading Jews met in London to discuss supporting the embattled country.

The highly sensitive talks, held under conditions of strict secrecy, centred on the urgent need to raise large sums of money to bolster the struggling state.

Among those in attendance were Isaac (later Lord) Wolfson, the head of Great Universal Stores, and Marks & Spencer director Israel Sieff.

But also present was a British MI5 informant. He described those present as "a syndicate" and as "extreme Zionists," formed with the objective "of raising funds …to purchase arms , to finance propaganda."

But MI5 was most interested in the presence at the meeting of Cyril Ross, already marked down as a key supporter of the Irgun.

Ross had risen to prominence during the war as treasurer of the Committee for a Jewish Army. By 1947 he was considered by MI5 to be an Irgun agent and was under constant surveillance.

Agents tailing him were told that he had "a typical Jewish appearance [and] still wears long side whiskers."

By 1947 the government and MI5 were deeply concerned that either Irgun or Stern Gang operatives were planning an outrage in London.

One unnamed Jewish revisionist group was accused, in a top secret government briefing, of involvement in the "collection and concealment of explosives… for sabotage on London and possible attacks on public persons."

In May 1949 an MI5 report on "The Activities of Cyril Ross" appeared to reveal his role as a spymaster for Israel. A key passage said that in "a private conversation with a Jew known to be closely connected to the Israeli government, (Ross) stated that he had organised an excellent intelligence service in this country, with informants in every government department of importance. …Ross stated that he had now turned all his useful contacts over to [the Israeli legation at] Manchester Square and said that Israel now had a first class intelligence service in the UK."

Even as late as 1951, warrants were issued in 1951 allowing the tapping of Ross's phone and the interception of his post as he was "believed to be engaged in espionage on behalf of a foreign intelligence service."

Despite these concerns, Ross, who died in 1973, was made OBE in 1947 and spent many years as a highly engaged communal activist. He supported the JNF, the Jewish Blind Society, and the Ben Uri Gallery, becoming a well regarded amateur painter.