Sighting in Cergy, September 1991

The witness reported this sighting in July 2009, many years after it happened. They first placed it in September 1990 or 1991, then in a letter of September 2010 settled on September 1991, without giving the day. At dusk, they saw a large circular object moving slowly, which they estimated at 20 to 40 metres across. It gave off a steady rumbling sound. For three to four minutes, flashing lights of several colours were visible around its edge.

The object followed a straight path from northeast to southwest, at an estimated altitude of 100 to 200 metres. It then vanished by blending into the sky, without having changed course. The witness said they would file a report with the local police. With the second letter, they enclosed documents about the object's path and a sketch of what they had seen.

No other witness account was collected. Because so much time had passed, any investigation was difficult, if not impossible. GEIPAN classified the case as C, insufficient data.