SMU Associate Professor of Law Gary Chan suggested that the scope for challenging the Public Prosecutor's decision to charge someone is weakened by the current system - in which guidelines remain internal and are not published. Writing in the current issue of the Singapore Academy of Law Journal, he said that the Public Prosecutor should disclose the reasons for deciding to prosecute in a particular case, provided there are no disclosure risks and public interest is not compromised. Law Minister K. Shanmugam also weighed in on the issue in Parliament last year. He pointed out that there are layers of checks such as internal processes and reviews while untenable decisions are also open to court scrutiny. However, Associate Prof Chan argued that any challenge is currently restricted to the limits defined by the apex Court of Appeal. The court had ruled last year that the Public Prosecutor's discretion is not absolute and that it must be exercised in good faith and not breach the Constitution. But if kept within these limits, the scope to challenge through judicial review would be further weakened, argued Associate Prof Chan. He pointed out that the starting point is that the Public Prosecutor's decision is presumed to be constitutional - yet this cannot always be so "if some undisclosed and unknown reasons exist".