Sir Paul McCartney's 'McCartney III' solo album has been delayed by a week, due to "unforeseeable production delays".

The Beatles legend took to his social media pages to announce that fans will have to wait a little while longer before they can get their hands on the long-awaited follow-up to 1970's 'McCartney I' and 1980's 'McCartney II', which will now arrive on December 18.

He wrote: "Unforeseeable production delays have forced the release date of Paul's all-new all-Paul album 'McCartney III' to be moved back one week to December 18, 2020. Thank you to everyone for your patience, support and excitement for the album. We can't wait for you to hear it! - MPL (sic)"

The 78-year-old music icon recorded his new album over a nine-week period amid the coronavirus lockdown, and recently admitted he relished the unique experience.

He explained: "If you're on your own, you can have an idea and then very quickly play it. Whereas, with a band, you've got to explain it.

"Sometimes that's great ... but when you're just noodling around on your own, there's just a sense of freedom."

Macca never set out with the ambition of making his latest record.

He shared: "Most of it's new stuff. There are one or two [songs] that I hadn't finished and, because I was able to get in the studio, I thought 'OK, wait a minute, what about that one?' So I'd get it out and think, 'Ugh, oh dear.' And you'd try to figure out what was wrong with it, or why you didn't like it.

"In some cases the vocal or the words just didn't cut it, so you'd strip it all down and go 'OK, let's just make it completely different'.

"When I'd done them, I was going 'Well, what am I going to do with this?' And it suddenly hit me: this is 'McCartney III'. You've done it all yourself, like the others, so this qualifies."

And the 'Let It Be' hitmaker explained that he was simply trying "to have fun" during the recording process.

He said: "Because I wasn't aiming at a proper record release, I was just having a go. So I think it has ended up being exactly what it is - which is me not really trying very hard, except to have fun."