Poison at the Pueblo — Tim Heald

At an exclusive language school in the hills outside Salamanca, former British gangster Jimmy Trubshawe is discovered flat on his back in his luxury cabin, clad only in boxer shorts and white socks, his face an unattractive shade of purple. He is, of course, extremely dead. The cause is soon established as the ingestion of poisonous mushrooms. But was the unfortunate Trubshawe's fatal meal an accident--or murder? Alerted by his contacts in the Spanish Guardia Civil, Sir Simon Bognor decides it's his business to find out....