Ganga Prasad Subedi, one of 200 members on the Royal Advisory Council, was killed by a group of armed rebels who burst into his home on Saturday night in Jarbuta village in the western Surkhet district, a police official said.
The Royal Advisory Council is called by the king when he seeks consultations.
The sixty-five-year-old councillor is survived by his wife and four children.
Suspected Maoists last week burned down the home of the Royal Advisory Council standing committee's chairman, Parsu Narayan Chaudhari, in the south-western Dang district.
Central committee killing
Police said rebels on Sunday also shot dead Ramesh Malla, who served on the central committee of Prime Minister Surya Bahadur Thapa's National Democratic Party, in Chitwan, 120km south of Kathmandu.
The killings came at the end of a 3-day nationwide strike called by the Maoists, who ended a seven-month ceasefire on 27 August when the government rejected their demands for an assembly to redraw the constitution.
A police official said Nepalese delegates to an Interpol conference starting in Spain on 29 September would call for international arrest warrants against senior Maoists.
A Nepalese court on 16 September ordered rebel leader Prachanda, and 20 others, to appear within 70 days to hear charges over the January assassination of a senior police official.
Low profile battle
Prachanda, whose real name is Pushpa Kamal Dahal, makes few public appearances.
The government, after the end of the truce, declared the Maoists a terrorist group - meaning senior rebels could be arrested on sight.
One senior Maoist, Chandra Prakash Gajurel, was arrested on 20 August in the southern Indian city Madras as he tried to board a flight to Germany en route to London. Indian authorities said he was using a fake British passport.
Gajurel's wife Kalyani visited Madras on Saturday and urged India to grant her husband asylum, saying his life would be at risk if he were deported to Nepal.
More than 8000 people have died since the Maoists launched their "people's war" in 1996. Officials have reported 216 deaths since the end of the ceasefire.