(Footage of Prince William and Kate Middleton on tour in Sabah plays)
KESHA WEST, REPORTER: The last time the picturesque state of Sabah was thrown into the international spotlight was for a British royal visit. Prince William and Kate Middleton travelled to the northern tip of Borneo last September, to take a tree top tour of Sabah's rain forest.
But it's a royal visit of an entirely different kind that is has now thrust the resource-rich state back into the international headlines.
A month ago, the self-styled Royal Sulu Army arrived on the shores of Sabah from the Philippines, asserting a long dormant sovereignty claim in the name of the Sultan of Sulu.
RAUL HERNANDEZ, PHILIPPINE FOREIGN AFFAIRS SPOKESMAN: There's a group there that, of about more or less 200 and some of them are armed or their escorts are armed. And we are calling on them to leave Lahad Datu as soon as possible, so that the issue will not escalate for them.
JAMALUL KIRAM III, SELF-PROCLAIMED SULTAN OF SULU (translation): My people are already there. We will not budge. We will not leave. If we die, then we die.
KESHA WEST: After a three week stand-off, on March 5th Malaysia forces launched a massive air and ground counter offensive to end the siege and flush out the armed group, believed to have been hiding in the state's east.
But the security crisis is far from over, reports say up to 70 people have been killed in the clashes.
The hunt for militants has also led to reports of mistreatment of the 800,000 Filipino migrants living in Sabah, thousands of whom have now fled back to the Philippines.
Offers of a cease-fire from the Sulu side have been rejected by Malaysia.
NAJIB RAZAK, MALAYSIAN PRIME MINISTER (translation): They must lay down their weapon and surrender unconditionally. The weapons must be submitted to us.
KESHA WEST: The US has refused to be drawn into the Sabah conflict, saying it is a matter for the governments of the Philippines and Malaysia.
The history behind this crisis is long and complicated. The territory was first given to the Sulu Sultanate by Brunei centuries ago. After World War II, it became part of Malaysia, but Kuala Lumpur still pays a token rent to the heirs of the Sultan of Sulu.
The Philippines originally agreed not to pursue the sovereignty claim but some in the administration have suggested it might be time for the claim to be re-examined.
AMINA RASUL, PHILIPPINE CENTRE FOR ISLAM AND DEMOCRACY: They have the authorisation given by the Sulu Sultan to pursue the Sultanate's claim over Sabah, the sovereign claim. And the idea had always been to bring this to the International Court of Justice. Unfortunately, you need two parties to agree and it seems that the Malaysian government has not agreed to bring the claim to the ICJ.
KESHA WEST: First complicating matters is the issue of who the real Sultan of Sulu is. There's said to be up to 10 different claimants to the informal but culturally influential title, including the Sultan of the moment Jamalul Kiram III.
(Photographs of four claimants are shown: Muedzal-Lail Tan Kiram, Fuad Kiram, Esmail Dalus Kiram II and Jamalul Kiram III)
AMINA RASUL: There are at least four claimants to the throne who belong to the bloodline. And, therefore, they have legitimate - they can be considered as a legitimate claimant.
KESHA WEST Andres Linholm says he is the chancellor of the only rightful Sultan of Sulu.
ANDRES LINHOLM, CHANCELLOR, SULTAN MUEDZAL-LAIL TAN KIRAM: Sultan Muedzal-Lail Tan Kiram is the only claimant who actually is a crown prince, whose father was the last recognised Sultan of Sulu and who lives actually lives in Sulu on Jolo island as well. The rest of the claimants they live in Manila.
KESHA WEST: As debate continues over who is the rightful Sultan, so too do the flurry of meetings over how to resolve this crisis, which is now becoming a political thorn in the side for both countries' governments ahead of elections.
AMINA RASUL: On the Malaysian side you have Malaysian politics coming in, with the opposition groups and the Barisian Nasional, the administration party at each other over the way the Lahad Datu situation has been handled.
(Footage of demonstrations in the Philippines)
KESHA WEST: In the Philippines there's been a growing tide of public anger over the Sabah issue. Hundreds of Filipinos have taken to the streets, claiming president Aquino has turned his back on the Filipinos in Sabah and their legitimate claim.
AMINA RASUL: Most Filipino, not just Muslim Filipinos have all over are very supportive of the Filipino claim of Sabah. And if the perception is that our government is, shall we say, putting the Sabah claim on the back burner, preserving its relationship with Malaysia because of the peace process, this will not sit well with the Filipino population who will be going to vote in May.
KESHA WEST: Despite this, recent polls suggest Benigno Aquino still has an approval rating of well over 65 per cent.
Both Malaysia and the Philippines say they now suspect the involvement of a third party no orchestrating the Sabah siege.
Manila suspects the Sabah stand-off may be designed to sabotage a fragile peace process between the Aquino government and the main Muslim rebel group, the Moro Islamic Liberation Front. A peace process Kuala Lumpur has been brokering.