Ms Malik felt “cheated and duped” by FHM India, which “tampered” with the photoshoot, Ayaz Bilawala said.
FHM India has been asked to withdraw all copies from newsstands and pay $2m in damages, he said.
Editor Kabeer Sharma told the BBC the claims were false and that he had video to prove the shoot’s authenticity.
The actress is shown sporting the initials ISI on her arm. The photos for the December issue have caused a sensation in Pakistan for both the nudity and the initials of Pakistan’s controversial Inter-Services Intelligence spy agency.
“Ms Malik has been cheated and duped. She had a photoshoot, but there was no nudity. She had some clothes on,” Mr Bilawala told the BBC.
“In the photos that were shown to her [for approval] she had her clothes on.
“She has suffered from a loss of reputation and we are demanding damages and withdrawal of the magazine from newsstands,” he said.
FHM’s editor confirmed to the BBC that it had received the legal notice.
“We have seen the notice and forwarded it to our legal department for appropriate action,” Mr Sharma said.
“All the allegations are false and we are looking at various options, including filing a countersuit,” he said.
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.