The official also said Lumley was taking a key interest in Pun´s plight because he saved her father´s life during World War II.
"She is going to his home in Pokhara later this month and I don´t expect she will be happy until the matter is resolved," Gaeso Chairman Santosh Thalak said.
The Gaeso said it is disturbed over reports that a distinguished former soldier is in danger of losing his house in Pokhara.
Gaeso said World War II veteran Pun is not able to pay crippling medical bills. Pun is the holder of the UK´s highest military medal for courage, the Victoria Cross.
"We are obviously very worried about Pun´s plight," Thalak told the BBC.
"He is a celebrated soldier who is currently in a fragile medical state receiving treatment here in Britain. He is not in a position to cope with having his home re-possessed and the authorities in Nepal should put a stop to it."
Reports said Pun owes nearly $18,000 to a finance company from which he took the loans to cover the medical costs and that the company has announced auctioning of his house to recover its investment.
The former rifleman won the right to live in the UK in 2007 after his case was supported by Ms Lumley.
Local activists in Nepal are also calling on the Nepal government to help Pun.
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