Radiohead will release the CD and vinyl versions of their latest album In Rainbows on 31 December.
Radiohead's single Jigsaw Falling Into Place is out in January
The band released the download version in October, and fans were invited to put their own price on the 10 MP3 files that made up the album.
Radiohead rejected recent press reports that claimed two-thirds of downloaders paid nothing - but did not reveal their own figures.
Internet monitoring company Comscore found the average price paid was £2.90.
US fans were the most generous according to Comscore, paying on average $8.05 (£3.85), compared with the $4.64 (£2.22) paid by those outside the US.
But the press release from Radiohead's representatives disputed the figures.
"The figures quoted by the company Comscore Inc are wholly inaccurate and in no way reflect definitive market intelligence or, indeed, the true success of the project," read the statement.
"As the album could only be downloaded from the band's website, it is impossible for outside organisations to have accurate figures on sales."
A spokesperson for Radiohead said the band's own figures were "not for public consumption" as "people were still downloading it [the album]".
The study was based on data gathered by observing the transactions made by "a few hundred" downloaders, a senior analyst for Comscore said.
"There is a small margin of error. We are confident in our data," he added.
Radiohead's single Jigsaw Falling Into Place will be released on 14 January.