Coldplay new album release date: Mystery poster seems to reveal when to expect A Head Full of Dreams

Frontman Chris Martin has described the upcoming record as 'like the last Harry Potter book or something'

Beady-eyed Coldplay fans have deduced that a mysterious poster spotted on the London Underground is an advert for the band’s new album.

Expected to be called A Head Full of Dreams, the record will follow 2014’s Ghost Stories on 4 December this year, just in time for Christmas.

Rumours began circulating on social media that the image of a multi-coloured, geometric Flower of Life against a black background was the artwork for the group’s seventh album, after some fans noticed that frontman Chris Martin had been wearing a T-shirt with a similar design at the Global Citizen Festival in New York.

Few details have emerged about the album, but Martin recently described it as “like the last Harry Potter book or something like that”, sparking speculation that it will be their final release.

“Not to say that there might not be another thing one day, but this is the completion of something,” he said. “I have to think of it as the final thing we’re doing. Otherwise we wouldn’t put everything into it.”

Some fans are theorising that new music, possibly above single "Amazing Day", will be released either today or next Friday.