Seeking to ease the diplomatic spat with New Delhi over the detention and ill-treatment of over 200 Indian IT professionals, Malaysia has conveyed "deep regret", sent police apologies and assured that the officers who violated procedures will be punished.

"We are not so proud as to not apologise if there is a mistake committed by our enforcement officers," Deputy Prime Minister Abdullah Ahmed Badawi told reporters on Thursday.

"I have already informed (home) ministry to take whatever action is necessary, and regarding the complaint to say that we are sorry for what has happened," Abdullah, who succeeds Prime Minister Mahathir Mohamad in October and is acting prime minister when Mahatir travels overseas, said in Port Klang.

"What is important is we want the bilateral relations between Malaysia and India to be good all the time and to improve," Abdullah said.

The home ministry in a statement said it "expresses deep regret over the inconvenience experienced by those detained. The police failed to inform the Indian High Commission of the action to be taken against the Indian workers."

"The police officers who have failed to abide by the procedures during the operation will be investigated and disciplinary action will be taken against them. At the same time, procedures for such operations will be tightened so that future operations will proceed smoothly and speedily," the home ministry statement said.

The ministry said the police were still holding seven men -- four Indians and three Pakistanis -- who had either overstayed or did not have proper documents.