The cargo ship SS Politician, which had 28,000 cases of whisky, sank off Eriskay in Western Isles 75 years ago.
Eight bottles of the whisky were recovered by a diver in 1987.
The National Trust for Scotland (NTS) has suggested that two bottles it has on the Isle of Canna could be added to these eight known bottles.
The bottles in the care of NTS are kept at Canna House and belonged the late John Lorne-Campbell and his wife Margaret Faye-Shaw, who gifted the property and Hebridean island to the trust.
Fiona McKenzie, archivist at Canna House, said: "According to the previous archivist, the bottles have 'always been at the house'.
"She was here from the 1960s and that's well before the diver brought up eight bottles in 1987. So looks like we may have two bottles that are not included in the official stats."
Many other bottles were salvaged from the SS Politician at the time of its sinking in 1941 and still thought to survive, but have not been officially recorded.
Hundreds of cases of whisky were hidden from customs officers by islanders. Some locations of these secret stashes have since been forgotten, according to islanders today.
The SS Politician was headed for Jamaica when it ran aground on the northern side of Eriskay in bad weather.
Scottish author Compton Mackenzie, published the novel Whisky Galore in 1947, which was loosely based on the shipwreck.
It was adapted for the cinema in a 1949 Ealing comedy.
Two bottles of whisky recovered from a shipwreck that inspired the book Whisky Galore may have been missed from official statistics.