Paris-based lawyer William Bourdon, who was in Penang yesterday, said the probe would probably reveal relevant details related to Altantuya's involvement in the purchase of the two French submarines by Malaysia.
Police investigations have already revealed that Altantuya and Abdul Razak Baginda, a close confidante of Prime Minister Najib Razak, had been beneficiaries of travel expenses paid by an obscure French company in Malta.
Bourdon (left), who was detained by immigration officers at the KL International Airport upon arriving from Penang about 10.30am today, said he had kept abreast of Altantuya's case since her death in 2006, and had noted that her murder trial had been overly dramatised.
Speaking to Malaysiakini in exclusive interview just hours before he was detained by immigration authorities, who boarded his plane at KLIA this morning, Bourdon said: "The manner in which the trial was conducted provoked many questions; a lot of obscurity remains regarding her murder."
The trial ended in 2008 with two of the bodyguards of Najib, who was then deputy prime minister and defence minister, being convicted of her murder.
The duo are currently appealing their death sentence. Abdul Razak, who had been charged with abetting the duo, was acquitted without being called to make his defence.
Observers had remarked that despite the high-profile trial, two pertinent questions surrounding Altantuya's murder were yet to be answered: why was she killed and who ordered her killing?
Najib, who as defence minister was in charge of the mega-Scorpene submarine deal, has denied any involvement in the murder.
On the Suaram case which the lawyer filed in Paris last year, Bourdon said he was confident he would be able to access the related documents and files very soon.
These expose is expected to bring to book high-profile Malaysian officials who are said to have received kickbacks amounting to millions of ringgit from the submarine deal.
Bourdon said the case was still under the investigation phase, where the police still interrogating witnesses.
If accepted, he said, an investigative judge will be appointed to handle the case.
"The investigative judge is the only real independent institution to deal with sensitive cases such as corruption," he said.
"The judges in such cases answer to no political hierarchy, so there is at least a legal guarantee that ensures their independence," he added.
"There can be no real democracy if judges are not independent."
However, Bourdon does not discount the fact that in sensitive cases like corruption, there could be a possibility of the public prosecutor being approached to keep the truth from coming out.
"Especially if the truth is dangerous (to the people who approach the prosecutors)," he said.
"Which is why we need an independent media to balance between state power and these institutions," he said, adding quickly that he was aware of the current state of the media in Malaysia.
Although Bourdon - who was accompanied by his lawyer wife, Lia Foriester, in his trip to Malaysia - is confident that the case is making headway in France, he is still careful not to be presumptuous on whether Suaram would eventually be accepted as a civil plaintiff.
This is due to the circumstances in any case involving corruption, which can be very challenging anywhere in the world, he said.
The public prosecutor could well deny Suaram the right to appear as civil plaintiff and if this happened, Bourdon said, he would definitely file an appeal.
Even if Suaram failed to make it to court, there would be the opportunity for its lawyers to access the relevant documents and files in the case.
"In my opinion, if Suaram is not accepted as a civil plaintiff, it would seem like a breach of international legal standards and law," Bourdon added.
Bourdon himself has been involved in battles to make government leaders accountable for their corrupt ways and in issues of human rights abuse over the past 30 years.
He set up Sherpa, a non-profit organisation, with other lawyers in Paris in 2005 to work on international justice cases.
He has conducted about 50 monitoring missions in several countries.
During the course of his work in various countries, the authorities have threatened him with deportation - but never went through with it.
They did, however, monitor his movements and he felt he was 'in permanent control by the secret police', for example, in Tunisia and Turkey, from 1995-2005.
In all these years, his team has not only registered defeat but there have also been several victories.
For example, in a forced labour case between France and Thailand, his intervention helped secure a better life and working conditions for his clients.
Bourdon said he has realised that these days citizens, from Malaysia to Tunisia, were no longer tolerant of corruption.
"In the last 20 years, there has been a sense of resignation where corrupt practices are in a way 'acceptable' but not any more," he said.
"What has become important is democracy and rule of law, and corruption involving government leaders can break the confidence of public votes," he added.