It was an unremarkable sunny, summer’s day at lunchtime when something strange appeared in the sky over Aldeburgh: Germans, or aliens?

The beds were made, the room was dusted, and Agnes Whiteland took a moment to gaze out of her window in Aldeburgh to see if anyone interesting was passing by - what she saw that lunchtime haunted her for the rest of her life. It was 1916 (or 1917, this part of the story is slightly hazy) and war was raging in Europe with terrible bloodshed and the loss of a generation: but at home, all was not quiet on the Eastern front. In 1915, Zeppelin air raids had led to panic in Suffolk as bombs fell from the sky at nearby Henham Hall and Southwold, before attacking Lowestoft. The creation of Count von Zeppelin's hydrogen flying machine unleashed the full horror of aerial warfare on the east coast, leaving terror in its wake and civilians feeling vulnerable on the home front for the first time. But Agnes Whiteland was convinced what she saw that day was no Zeppelin: for a start, the craft was silent, secondly, there were no bombs.

On August 8 1968, Alfred Whiteland, who was born in 1910, saw the letter he had written to the Daily Mirror published. "My mother has often told the following story over the years and, as she is eighty-four, I would like to find out for her who these mystery men were and what they were doing. This is the story," he wrote. "It was about the middle of World War One and on a weekday. Mother was living at Aldeburgh, Suffolk. She had gone upstairs just before dinner, opened the casement window and looked out to see who might be on the road.

"Having looked up and down and noticed there was no one in sight, she was about to step back when something urged her to look again. A little above the level of the house eight to twelve men appeared on what seemed to be a round platform with a handrail around it. This they were gripping tightly.

"She could see them so clearly. They were wearing blue uniforms and little round hats, not unlike sailors. She heard no sound from the machine as it came off the marshes. It turned a bit and went over the railway yard to disappear behind some houses. Have you any explanation for this?" The so-called 'Aldeburgh Platform' hovered just above a shed around 8m high and turned surprisingly quickly and with great agility at a right angle before it disappeared. "Mother says that she kept wondering what was making the thing move, and looked up in the sky and then at the men and then in between their legs to see if there was an engine there in the middle, but she could see nothing there," wrote Mr Whiteland Junior, who died 18 years after his mother in 1989.

The Zeppelin theory was quickly dispatched: researcher Charles Grove wrote to Charles Gibbs-Smith of The Victorian & Albert Museum to ask if the craft could have been an observation platform below one of the German warships. No, he was told, as such platforms only carried one man who would be lying down and Zeppelins were notoriously noisy. UFO researcher Carl Groves wrote to Mr Whiteland to find out more information, asking a list of questions and asking for sketches - he received all his answers, plus drawings in response. He learned the craft was travelling at the speed of a running man, that Mrs Whiteland saw it for around four minutes, that it was seen on a bright summer's day at around midday and that no one else in Aldeburgh reported having seen it.

Mrs Whiteland never did receive any answers as to what she had seen that day, but others did come forward with similar stories: a Mr Graham wrote to Alfred to say that his mother, who lived nearby in Aldringham Fen, had seen an airship lower an observation device hundreds of feet below it while a Mr Winslow of London said that plaforms beneath airship baskets could, indeed, hold several people. But 12?

In October 1955, long after Zeppelins flew over Britain, the Reverend Pitt-Kethly was travelling on the Uxbridge train line to East Harrow when, at the West Hampstead viaduct, he saw a reddish-brown and grey platform the size of a small bus at around 120ft in the air. It was carrying around 20 men wearing helmets and in khaki uniforms and moved slowly and silently in his eyeline for around three or four minutes. Rev Pitt-Kethly, when addressed with the theory that what he saw was the reflection of a double-decker bus, replied that he "did not doubt the evidence of my own optics".

Interestingly, Agnes' husband Ernest also saw something strange, albeit on the ground. In 1938, as he walked close to Ditchingham Station, he saw Black Shuck