The SEC Act also does not regard all shareholders as insiders in the offence of insider dealing, Marsoof told a seminar on stock market offences organised by the SEC.
The SEC Act contains provisions which expose public servants or former public servants to liability for insider dealing, he said.
"This provision does not extend to members, officers and servants of the SEC as they are simply not 'public servants'," Marsoof said in a paper prepared for the seminar.
"A serious deficiency in the SEC Act is the glaring omission to provide against the use of price sensitive information gathered in the course of the discharge of their duties by (SEC officials)."
The Takeover Code provisions will cover such officials but are restricted to the offer period.
However, Marsoof said, SEC members or officials who trade in listed securities using price sensitive information acquired by virtue of being a director or connected to a company, can still be liable for insider dealing under section 32 of the SEC Act.
"It is useful to consider some special categories of persons who are or ought to be liable for insider dealing in the context of the SEC Act," he said.
He also said that while directors, officers and employees of a company are clearly considered insiders under the SEC Act, an ordinary shareholder would not be regarded as an insider.
"Curiously, all shareholders are regarded as insiders in the current UK legislation. The United States seeks to strike a balance between these two extremes and regards only controlling shareholders as insiders."
Marsoof said it is necessary to consider amending the SEC Act to cover shareholders more comprehensively.
He also suggested the need to consider synchronising provisions in the SEC Act and the Takeover Code..