But these are real-life events, and they could set back the chances of Malaysia's ruling coalition in an election that Prime Minister Najib Razak must call by midyear.

Mr Najib denies involvement but the allegations will not go away. The internet in Malaysia is running hot with allegations by a disaffected businessman, Deepak Jaikishan, who is well connected in the ruling United Malays National Organisation.

They relate in part to the alleged cover-up of the murder of 28-year-old Mongolian fashion model and translator Altantuya Shaariibuu in a patch of jungle in the Kuala Lumpur suburbs in 2006.

The second part of the controversy is driven by an inquiry in France into a complex money trail left by Malaysia's $US2 billion purchase of two French-Spanish built Scorpene submarines in 2002 while Mr Najib was defence minister.

Ms Shaariibuu worked as a translator in the latter stages of the deal negotiations.

The link between the two events is a Ferrari-driving businessman, Abdul Razak Baginda, one of Mr Najib's best friends and policy advisers, who was the director of the Malaysian Strategic Research Centre.

Mr Najib, who is preparing to contest his first election since being installed in power by his party in 2009, denies ever meeting Ms Shaariibuu or having any link with her. The government denies any wrongdoing in the submarine purchases.

But it was two of Mr Najib's bodyguards who dragged Ms Shaariibuu from a car, knocked her unconscious and shot her twice in the head on October 19, 2006, according to court testimony. She had begged for her life and apparently that of her unborn child.

The killers then wrapped her body in C4 plastic explosives obtained from the military and blew her up, ensuring the foetus was destroyed along with the identity of the father. For good measure, they erased her entry into Malaysia from immigration records.

The Scorpene submarine story has been tumbling out since 2002 when Mr Najib ordered them from French ship builder DCNS.

Two French investigating magistrates are looking into so-called ''commission'' payments of about $US160 million into companies reportedly set up by Mr Baginda. Documents have been seized from the DCNS offices in Paris.

Ms Shaariibuu, who spoke several languages, became Mr Baginda's lover after they had met in Hong Kong. Stunningly beautiful, she had been married to a popular Mongolian singer and to the son of a famous Mongolian fashion designer.

Ms Shaariibuu admitted in a letter found after her murder that she had been blackmailing Mr Baginda, who had jilted her after they had travelled through Asia and Europe together.

She reportedly had wanted a $US500,000 cut to remain silent about her knowledge of the deal.

Ms Shaariibuu was abducted outside Mr Baginda's house, where she was said to be causing a scene. Her murder was eventually uncovered following continued pressure from her well-connected family and the Mongolian embassy in Kuala Lumpur.

The two bodyguards were convicted of murder in 2009 but have claimed they are scapegoats and are appealing against death sentences. Pleading with a court not to execute him in February 2009, Sirul Azhar Umar described himself as a ''black sheep that has to be sacrificed'' to protect unnamed people.

''I have no reason to cause hurt, what's more to take the life of the victim in such a cruel manner,'' he said.

''I appeal to the court, which has the powers to determine if I live or die, not to sentence me so as to fulfil others' plans for me.''

A judge sensationally dropped an abetting a murder charge against Mr Baginda in 2008 before any evidence was heard and he is believed to be living in exile in Britain with his family.

Among several claims made by Mr Deepak - a carpet dealer - to opposition and independent websites are that he interceded to have a private detective change his 2008 sworn declaration that Mr Najib had had a sexual relationship with Ms Shaariibuu. The Prime Minister has repeatedly denied any relationship with Ms Shaariibuu, calling it a ''terrible lie''.

Often sensational claims and counter claims in the case have been barely reported in Malaysia's government-controlled mainstream media.

The Malaysian human rights non-government organisation SUARAM, whose approach to a magistrate in Paris in 2010 prompted the French investigation, has complained of official harassment.

But the claims are hot issues on opposition and independent websites, led by the Hong Kong-based Asia Sentinel online magazine, which published confidential files on the case last year and whose editor, John Berthelsen, has doggedly pursued the story for years.

Malaysia, with a population of 28 million, has an internet penetration of more than 62 per cent, one of the highest in south-east Asia.

Some commentators in Kuala Lumpur, including Wong Choon Mei writing in the Malaysia Chronicle, have speculated that 59-year-old Mr Najib could be forced from office before he gets to call the election. Jittery powerbrokers in UMNO fear that if he remains head of the coalition, they may lose to the opposition leader, Anwar Ibrahim, and his Pakatan Rakyat coalition.

There is infighting in UMNO, which has shared power in the country for more than 50 years, as the latest opinion polls show Mr Najib's approval rating has fallen to its lowest level in 16 months.

Wong wrote in the Chronicle on January 7 that UMNO watchers believed former prime minister Mahathir Mohamad had decided to throw his weight behind Deputy Prime Minister, Muhyiddin Yassin, and effect an 11th-hour change in leadership, although many have cautioned that such a move could boomerang and create even greater infighting.

But Mr Najib, the son of Malaysia's second prime minister, has emerged unscathed by the prosecution of his bodyguards and is publicly ignoring the French inquiry and Mr Deepak's claims as he presents himself as a reformist, abolishing several restrictive laws and implementing a program to bolster unity among ethnic groups.

Malaysia's economy has fared well and the country is considered by the Work Bank to be an attractive place to do business. On January 8, Mr Najib denied rumours he had suffered a minor stroke due to the pressure of the allegations by Mr Deepak, saying he is healthy. ''So don't listen to the blogs, please,'' he said.

Analysts say the election will be the strongest ever challenge to UMNO's rule. Mr Najib has called the coming election ''a defining point for the destiny of the people and country''.