A row has erupted over an image of Pakistani actress Veena Malik sporting the initials ISI on her arm, with FHM India insisting it is not fake.

It has caused a sensation in Pakistan for both the nudity and the initials of Pakistan's controversial Inter-Services Intelligence spy agency.

Pakistani media have quoted a spokesman for Ms Malik as saying she never took part in such a photoshoot.

But FHM India's editor told the BBC that nothing had been doctored.

"We have video footage of the shoot as well as emails from Veena about how she's looking forward to the cover," Kabeer Sharma told the BBC's Nosheen Abbas in Islamabad.

"The idea to have ISI written on her arm was mine, and it was Veena's idea to have it in block letters," he added.

He said that the image was intended to be playful, saying that: "In India we joke about this... if anything goes wrong... we say the ISI must be behind this."

The ISI has been in the headlines in recent months after senior US officials accused it of supporting militants based in Pakistan's tribal areas who target Western troops in Afghanistan.

In September the most senior US military officer Adm Mike Mullen said that the Haqqani militant network "acts as a veritable arm of Pakistan's Inter-Services Intelligence Agency".

Pakistan has vehemently denied such allegations.

Pakistan outrage

Correspondents say that the image, which is the cover of the December issue of the Indian edition of the global men's magazine, has caused a storm in Pakistan with many people expressing outrage over the nudity and the boldness of the photo.

Many Pakistanis on the micro-blogging site Twitter are also expressing bemusement at the image.

The Express Tribune newspaper in Pakistan said a representative of Ms Malik had denied she posed for the shoot.

"Veena knows her limits. I know we have done quite bold stuff/shoots, those which are available on our website, but she knows her parameters," Sohail Rashid is quoted as saying.

FHM's editor said he had never heard of the representative and added that Ms Malik had not got in touch to ask him to modify or remove the image.

The actress has been at the centre of controversy before.

She caused outrage among conservative circles in Pakistan for appearing on the Indian reality show Bigg Boss in 2010. She hit the headlines again in March this year by challenging the views of a Pakistani cleric on television.