Revealing a new theory on the 2001 palace massacre, former Nepal king Gyanendra's son Paras has claimed that crown prince Dipendra was not drunk during the killing and a thwarted major arms deal might have been the 'real trigger' behind it.

Speaking for the first time about the killing of King Birendra and his entire family, Paras, who has been staying in Singapore since the abolition of monarchy in Nepal, also claimed that in 2000, Dipendra told him and some other palace youngsters that he wanted to 'bring down the ivory tower'.

In an interview to The New Paper of Singapore, the former crown prince, known for his flamboyant lifestyle, said the royal family's opposition to Dipendra's affair with Devyani Rana was only one of the three reasons for the killing -- the other two being the prince's craze for money and power.

According to 37-year-old Paras, his cousin's advisors had been working on a multi-million dollar arms deal, which could have brought the crown prince a 'windfall. It would have been Dipendra's golden parachute to freedom, he said.

"The Nepali army was looking for a new weapon to replace the Belgian SLR. Dipendra liked the German Heckler & Koch G36 assault rifle, as opposed to the battle-tested Colt M16," said Paras.

"But his father, His Majesty, did not agree. I know that they argued over it. Dipendra was frustrated. He wasn't happy. That, to me, was the real trigger (for the massacre)," Paras told the paper.

According to Paras, Dipendra 'had his reasons' to kill the king, the first being Birendra promulgating a new constitution and ending almost 30 years of absolute monarchy.

"After his father told him in 1990 about the plans to give up the monarchy, Dipendra was never the same. He never agreed with that as he wanted to rule the country. I think he started planning his moves then," said Paras.

According to an official probe panel, Dipendra, who was drunk, killed his father Birendra, mother Aishwarya [Images], brother Nirajan and other family members before turning the gun on himself on June 1, 2001.

However, the report was dismissed by many and some conspiracy theorists even point a finger at Gyanendra, the king's brother, and Paras, who were the only beneficiaries of the incident.

Paras' interview came out at a time when Nepal premier and former Maoist leader Prachanda has spelt out a plan to reinvestigate the palace massacre.

Paras also claimed that Dipendra was not drunk and there was 'no smell of alcohol on him' when he saw him earlier that night. He was behaving abnormally, acting as though he was drunk when he clearly was not, Paras alleged, and added that a hint about his plan was given by Dipendra in 2000 itself.

"He had talked to us (the younger generation of Nepali royalty) about it a year before it happened...I remember it clearly. It was his birthday (in 2000) and he told all of us that he would bring down the 'ivory tower'. But we didn't take him seriously. How could we," recalled Paras.