London commuters listening out for the latest news about train services got a broadcast with a difference when the noise of a couple apparently having sex was blasted out over a station's loudspeaker system.

Instead of the usual messages about delays, passengers at West Ham station in east London heard a couple's love-making antics being relayed over platform loudspeakers during the evening rush hour yesterday.

"The noises heard by passengers were not from within our station. We believe they were a result of some sort of interference with our public address system," a Transport for London spokesman said today. "It certainly wasn't coming from our staff."

He said the station's public address system worked on radio waves and somebody must have been broadcasting on the same wavelength. He said staff had turned off the loudspeakers as soon as they realised what was going on.

"It was definitely a couple doing it there and then," passenger Laura O'Connor told the London Evening Standard newspaper. "He was grunting loudly and she sounded like she was having a great time. The driver must have heard it, too, as the doors stayed open longer than usual."