Simon, who is native to Sabah, is the former state secretary and vice-chairperson of the Human Rights Commission (Suhakam).
In a press release today, Proham said that it was of utmost importance that the RCI is capable of restoring and raising public confidence on this matter.
"(The RCI must ensure) that ample opportunity and vigilance is maintained in (the) investigation and disclosure of all data and issues pertaining to this critical matter, well before the coming election," said the group.
The press release was signed off by three Proham members - Transparency-International Malaysia deputy president Ramon Navaratnam and two Suhakam members Hamdan Adnan and Denison Jayasooria.
Proham also outlined three key goals which must be incorporated into the terms of reference for the Royal Commission of Inquiry (RCI) into allegations of illegal immigrants being given citizenship in Sabah.
The first goal is to investigate the sudden rise in Sabah's population.
"(The rise) is unusual and not consistent with normal demographic developments and certainly according to average population growth anywhere in Malaysia.
"The only exception may be Selangor which has been facing similar problems," said the group in a press release today.
Secondly, the terms of reference should also ensure the investigation into procedures used in issuing citizenship in Sabah and hear complaints from locals.
Third, and finally, Proham said the terms of reference must also include devising new procedures that will prevent any alleged abuses of the past in registering new citizens.
The group said that the findings of the Suhakam roundtable discussion in 2006 - chaired by Denison - will serve as a useful reference.
Proham noted that the RCI was long overdue. Its establishment illustrate the success of civil society advocacy and work done by Suhakam, said the group.
"The government is to be commended for finally responding to this urgent call of Sabahans for clean, transparent and fair registration of citizens," they said.
Why the news blackout?
Proham was commenting on de facto Law Minister Nazri Abdul Aziz's written reply to the Dewan Negara yesterday that the terms of reference was being constructed.
In a separate press release, veteran opposition lawmaker Lim Kit Siang pointed out that Nazri's reply to the Dewan Negara was completely blacked out in the Sabah dailies.
Lim argued that rightfully, the news should have made it to the front-pages of all Sabah newspapers.
He said newspapers over in Peninsula Malaysia were not much better, with the exception of The Sun, Star Online and several news portals.
"Is it true that Bernama, which had earlier yesterday sent out a news bulletin on Nazri’s parliamentary answer confirming the Cabinet decision on Feb 8 to form the RCI, had a few hours later sent out a retraction of the news item?
"What right has Bernama to 'kill' Nazri’s answer in Parliament, even if Nazri had misled and not told the truth in Parliament?
"Will there be answers to these questions?" he asked.