A valuable medal awarded by Joseph Stalin to one of New Zealand's little-known war heroes is part of a rare set going under the auction hammer in London this week - and his nephew is appealing for help to bring it home.

Wing Commander Henry Neville Gynes Ramsbottom-Isherwood led the 151 Fighter Wing in north Russia during 1941 and 1942, helping Stalin's forces fight the Nazi invasion.

Ramsbottom-Isherwood, born in Petone, joined the RAF because New Zealand did not have an air force, and served until his death, test-flying a fighter jet as late as 1950.

Before moving to England, he had won local fame by scoring all of Marlborough's points in its first, unsuccessful Ranfurly Shield rugby challenge.

He won eight medals during the war, and was one of only four non-Soviet recipients of the Order of Lenin.

The medals are expected to attract bids of £30,000 ($76,500) at the Sotheby's auction on Wednesday. An accompanying set of miniatures is expected to go for around £1500 ($3800).

The war hero's nephew, Neville Ramsbottom-Isherwood of Wainuiomata in Hutt City, was blindsided 11 days ago when he heard about the auction. It emerged that his uncle's daughter, India, found the medals while moving house earlier this year. Ramsbottom-Isherwood said India, who is elderly, was persuaded to sell the medals to fund her ongoing care.

He contacted Defence Minister Wayne Mapp, his local National MP Paul Quinn and the National Army Museum at Waiouru with a plea to buy the medals and put them on display.

"The thing that scares me is if they don't come back to New Zealand now, they'll never come back," he said.

Mapp told Herald on Sunday yesterday that the Air Force Museum in Christchurch was the most logical institution to consider buying the medals. He planned to speak with the museum tomorrow.

Ramsbottom-Isherwood will bid by phone for the miniature set.

"My wife will have her finger over the button. I have a limit, but what price do you put on your heritage?"