A British spy who helped lead the French Resistance during World War II outfoxed the Nazis by concealing secret messages in the hem of her skirt, according to records unsealed March 31.

Britain's National Archives opened its records on Pearl Cornioley, who parachuted into France posing as a cosmetics saleswoman to deliver coded messages to Resistance members. The release follows her death on Feb. 24.

The records shed light on a woman who quickly adapted to life as an agent but never forgot about her family back home, requesting in handwritten notes that officials in London send her mother and sisters birthday and Christmas presents.

The National Archives released two packets of information, detailing Cornioley's training as a special agent, her activities in the war and her struggle to have her service recognized.

Ms. Cornioley, whose nom de guerre was Genevieve Touzalin while in France, had been educated in Paris. She escaped France ahead of the Nazi invasion and returned to Britain via Spain.

Upon returning to Britain, she worked briefly at the Air Ministry but used her French to gain a slot as a Special Operations Executive agent – one of about 40 women to serve. The Special Operations Executive evolved into today's Secret Intelligence Service, the MI6.

Early in her training with the Special Operations Executive, supervisors said she lacked the natural moxie to excel as an agent, but she compensated with her social nature, innate skill, and memory.

"She is of average intelligence and fairly practical, but rather slow in picking up new ideas. She has, however, a good memory and does not forget what she had learnt," a review of her training says. "Outstanding shot with pistol and other weapons. Probably the best shot (male or female) we have had yet."

After parachuting into France, Cornioley passed on secret messages to her first handler in France that she had carried in the hem of her skirt. The documents did not detail the contents of the messages contained.

Following the capture of her leader, she assumed control of the cell in the Loire River valley, about 240 miles southeast of the Normandy beaches.

She interrupted the Paris-Bordeaux railway line more than 800 times and attacked convoys in June 1944. All told, she led 3,000 French Resistance fighters in a host of guerrilla warfare missions.

She proved so crucial that the Nazis issued a 1 million franc award for her capture, hoping to quash her pivotal role in the Resistance.

"She's obviously a very brave woman. She goes through Gestapo lines, helps airmen escape to safety and baffles the Nazis in the field," said Mark Dunton, a historian specializing in World War II.