A handwritten message on their website says that recording sessions in Spain, and a tour of Latin America earlier this year, have influenced their sound.

"No maracas or castanets," the message said, "but a vibrancy and colourfulness that owes much to the atmosphere of Buenos Aires and Barcelona".

Coldplay's fourth album, the follow-up to 2005's X&Y, is due next year.

The group are among Britain's most successful acts, scoring international hits with songs like Yellow, Clocks and Fix You.

'Friction'

X&Y was the biggest-selling album in the world in 2005, and the band have admitted there has been "tension" in the recording studio as they try to follow it up.

"Tension is an inherent part of recording," a note on the group's website explained.

"Without tension, there's no focus. What is remarkable is that this friction very rarely ignites into flame."

The author, who uses the alias Prospekt, continued to say that the group had recently sat down with producer Brian Eno to review their progress.

"Very little material got an unreserved thumbs up from everyone. However, far from feeling dispirited, we all came out feeling a lot more confident.

"It feels a lot better to check the map and know which direction you're headed and how far you've got to go rather than wander around aimlessly and hope for the best."

Fans widely believe the new album will be titled Prospekt.