Left-wing US journalist was on Hoover's radar but then became an expert on British MPs' foibles
A Westminster institution for half a century, the bearded, bespectacled Andrew Roth condensed into numerous books -- especially his regularly updated Parliamentary Profiles -- a wealth of information invaluable to opponents, pressure groups, constituents... and obituarists. He also produced an acclaimed biography of Enoch Powell.
His assessments were pithy. The formidable Conservative Dame Irene Ward he termed "a backbench Brunnhilde: blonde, warm, dowdy, waddles". Margaret Thatcher was a "diamond-hard Rightist suburban feminist, cold-water English rose".
Insistent that he dealt in facts and analysis, not gossip, he also produced the weekly Westminster Confidential for embassies, foreign correspondents and the like. Subscribers got their money's worth: Westminster Confidential was first into print over the Profumo affair, and in 1992 it revealed, to acute embarrassment in Frankfurt, that the Bundesbank had set up a computer model to second-guess the Treasury's economic forecasts.
Roth, who became a naturalised British subject in 1966, was a lieutenant in US Naval Intelligence when, in June 1945, he and two government officials were arrested in Washington and charged with espionage.
The Amerasia case, named after a magazine that had received classified information, was the first round in the campaign against alleged communist infiltration of organs of the US government pursued by Richard Nixon and Senator Joseph McCarthy, backed up by J Edgar Hoover at the FBI.
Hoover was convinced that Roth was the brains behind an alleged spy ring, and ordered that his telephone and room be bugged. In the Navy as a Chinese specialist, Roth had unwisely introduced Emmanuel Larsen, a State Department expert on the Far East, to Philip Jaffe, editor of Amerasia. When British proposals for postwar Thailand appeared in Jaffe's magazine, Britain protested about a breach of security and the FBI discovered Jaffe had beguiled Larsen into handing over classified documents.
Jaffe was keen to contact a Soviet agent named Joe Bernstein to warn the Kremlin that elements of the American Right wanted to turn against Russia after defeating Japan. Roth warned him not to, adding that the issue was "wide open" to the American media. The FBI concluded that Roth was advising Jaffe how to pass on information without being caught.
A grand jury indicted the defendants, but the following February the charges were withdrawn for lack of evidence. Hoover was furious.
Several authors later repeated the spying charges against Roth; twice in the Fifties he won substantial damages from British publishers. Roth admitted having been a fellow-traveller as a teenager, but was adamant he had always been loyal to his country.
Andrew Roth was born in New York on April 23 1919, the son of orthodox Jews from Hungary; he lost 50 relatives in the Holocaust. He studied Social Sciences at the City College of New York, then Far Eastern History at Columbia University, the University of Michigan and Harvard.
After Pearl Harbor he joined the Navy over his father's objections, serving in intelligence until his arrest two months before VJ-Day. While awaiting trial he wrote editorials for The Nation. After the charges were dropped he joined the Toronto Star as a foreign correspondent, working in 20 countries before settling in London.
Roth soon detected a gap in the market at Westminster; he founded Parliamentary Profiles in 1953 and Westminster Confidential two years later. They became gospel for anyone wanting to know which MP was the grandson of Lord Curzon's mistress, or had been knighted once by the queen and twice by popes.
He chronicled exhaustively a steady increase in MPs' outside interests, and in 1961 caused a storm by calling, in the foreword to The Business Background of MPs, for a register of members' interests; 280 Conservative and 50 Labour MPs then held 490 directorships between them -- one Conservative, Sir Cyril Black, having 49. By 1966 Roth estimated that MPs shared more than 1,100 posts at director level or above.
Roth was one of the first to remark on new trends in lobbying. In 1974 he disclosed that many MPs were being paid to collect "intelligence" for companies seeking early warning of future government policy; he himself was frequently asked to act as a "talent scout" for firms wanting a suitable MP.
Roth also built a reputation as a fine biographer. There was particular praise for Enoch Powell: Tory Tribune (1970), in which Roth wrote: "Powell is the first figure in modern Tory politics who has tried to be a populist politician." Powell would not be interviewed, but agreed to correct matters of fact.
His next work of biography was Sir Harold Wilson: Yorkshire Walter Mitty (1977). Roth knew a great deal about Wilson, one of the few subjects on which he would be indiscreet. Both Harold and Mary Wilson sued for libel and breach of confidence; their lawyers persuaded some shops not to stock it, but publication went ahead.
The final profile Roth produced was Mr Nice Guy and His Chums: The 1992-93 Cabinet of John Major.
Andrew Roth was twice married: first, in 1949 (dissolved 1984), to Mathilda Friederich, and secondly, in 2004, to Antoinette Putnam. She survives him with a son and a daughter of his first marriage also survives him.