Scots pop singer Emeli Sande has said the Band Aid song needs rewriting and apologised if the latest version "caused offence".

The star, who was involved in the latest remake of Do They Know It's Christmas?, posted a message on Twitter in which she said lyrics she and African artist Angelique Kidjo recorded did not make the final version.

The song became the fastest selling single of the year - after just a day's sales following its release last week - and looks set to outstrip previous efforts on its way to a potential number one in the charts this weekend.

But there have been some complaints over the song's content, with some of the lyrics changed to reflect the Ebola crisis in West Africa.

Sande tweeted: "I've been having so many discussions about this all week. Here are my thoughts on the band aid single..."

Her message continued: "Ye, I agree the lyric needs changing. In fact I feel a whole new song is required. Angelique Kidjo and I made and sang our own edits. Unfortunately, none of these made the final cut.

"Aside from my feeling regarding the lyric, there was no doubt in my mind or heart that this project came from a place of pure and respectful intent. Sir Geldof made this clear when he addressed us all: I haven't heard a man speak with such passion and sincerity in many years.

"I am so proud of my Zambian heritage. No offence or disrespect to the beautiful and prosperous continent was ever intended. In my eyes, this song is specifically addressing a medical crisis, which is very real and in urgent need of awareness and support.

"The response from world governments has been horribly slow and media coverage has been minimal though thousands and thousands are dying.

"I apologise if the lyrics of the song have caused offence. I wish the changes had been kept but that is out of my control. The sole objective is to raise awareness and money to provide medical aid to those suffering the Ebola outbreak, which is being worsened and amplified by poverty.

"Thank you so much for your support."

The reworked version of Do They Know It's Christmas? features stars including One Direction, Bono and Ellie Goulding, and is expected to raise millions to help fight the Ebola crisis, which continues to grip parts of the continent.

Chancellor George Osborne agreed to waive VAT on the single's sales, so every penny will help the charity effort.

The new recording marks the 30th anniversary of the song, which was originally put together to raise funds for famine relief in Ethiopia.

Meanwhile, singer Lily Allen has revealed she turned down the opportunity to be on the new version.

She told the Mail on Sunday's Event magazine: "I got an email asking me to do it. It's difficult to explain why I didn't do it without sounding like a complete ****. I prefer to do my charitable bit by donating actual money and not being lumped in a with a bunch of people like that.

"It's like the success club and I'm not really in that club. I don't think I'm above it all - I'm way below it. But there's something a bit smug about it."

But she was full of praise for the man behind Band Aid, Bob Geldof.

"I actually don't mind Sir Bob. He doesn't give a **** and he's grumpy like me," she said.