Awarding the Nobel Peace Prize to US President Barack Obama in 2009 failed to achieve what the committee hoped it would, its ex-secretary has said.
Geir Lundestad told the AP news agency that the committee hoped the award would strengthen Mr Obama.
Instead, the decision was met with criticism in the US. Many argued he had not had any impact worthy of the award.
Mr Lundestad, writing in his memoir, Secretary of Peace, said even Mr Obama himself had been surprised.
"No Nobel Peace Prize ever elicited more attention than the 2009 prize to Barack Obama," Mr Lundestad writes.
"Even many of Obama's supporters believed that the prize was a mistake," he says. "In that sense the committee didn't achieve what it had hoped for".
He also reveals that Mr Obama considered not going to pick up the award in Norway's capital, Oslo.
His staff enquired whether other winners had skipped the ceremony but found this has happened only on rare occasions, such as when dissidents were held back by their governments.
"In the White House they quickly realised that they needed to travel to Oslo," Mr Lundestad wrote.
Mr Lundestad served as the committee's influential, but non-voting, secretary from 1990 to 2015.
He has broken with the tradition of the secretive committee, whose members rarely discuss proceedings.
The book also gives other insights into the activities of the committee:
According to Mr Lundestad, Jonas Gahr Store, then Norway's foreign minister, tried in 2010 to dissuade the panel from awarding the prize to a Chinese dissident, fearing it would strain the country's relationship with Beijing. The Nobel committee ignored the warnings and honoured Liu Xiaobo.
Mr Lundestad also criticises Thorbjorn Jagland, who was the committee chairman for six years and is now a regular member. He said that as a former Norwegian prime minister, Mr Jagland should never have been appointed to the committee, which frequently stresses its independence.
In an amusing anecdote, Mr Lundestad relates how he found Palestinian leader Yasser Arafat, who won the award in 1994, watching an episode of the Tom and Jerry cartoon in his hotel with other Palestine Liberation Organisation members. "It was made very clear that they intended to watch until the end," he said.
This year's Nobel Peace Prize will be announced on October 9.