London - British Prime Minister Gordon Brown said Monday that a racist remark made by Prince Harry about a fellow soldier was a "mistake" but he he believed the prince's knew what he said was "unacceptable."

Harry, 24, was reported at the weekend having referred to a fellow military cadet at Sandhurst military academy three years ago as ""our little Paki friend."

The video released late Saturday by the News of the World reportedly shows Harry when he was on manoeuvres in Cyprus in 2006.

Brown said on British television Monday that he believed the public would give Prince Harry the "benefit of the doubt" over the furore.

He said he believed the prince, who is third in line to the British throne, knew his comments were "unacceptable," but he believed his apology was genuine.

"I think the sincerity of his apology cannot be doubted. It was a mistake, he has made the admission of that and, once he has made his apology, I think the British people are good enough to give someone who has actually been a role model for young people and has done well fighting for our country, gone into very difficult situations with bravery, I think they will give him the benefit of the doubt," said Brown.

After the remark was reported late Saturday, Prince Harry through St James's Palace issued an apology but insisted that the comment was a nickname and not done in malice.

"Prince Harry fully understands how offensive this term can be, and is extremely sorry for any offence his words might cause," the statement said.

The army is investigating the incident. (dpa)