The government agency says it was forced to step in in March to carry out emergency work to prop up Skelbo Castle on the shores of Loch Fleet in Sutherland, after it was left to fall into disrepair by rare icon collector Mikhail de Buar.
However, officials were not aware that the Baron Skelbo, a friend and confidant of former Russian President Boris Yeltsin, who amassed a collection of rare religious icons worth 19 million following the collapse of the Soviet Union, died of cancer on 11 September last year, aged 70, leaving no will.
Under heritage laws designed to protect buildings of national importance, Historic Scotland can make repairs and then bill the owners for the work. But the agency has confirmed that under the circumstances it will not be able to retrieve the money it has already spent. However, it says it hopes the new owner will work with it to maintain the remains of 14th-century motte-and-bailey castle.
A Moscow court is currently attempting to sort out de Buar's legacy and is expected to announce who the new Baron Skelbo is later this year - believed to be the first time a foreign jurisdiction has decided the fate of a Scottish baronetcy.
Among de Buar's possible heirs to the title is his eldest son Andrei Vyazemshev, in his 20s, Mikhail de Buar junior, 19, and Irina Berezhnaya, who have sided with his sixth wife Tatyana in the court battle against his fifth wife Lyubov Elizavetina for his fortune.
While local heritage groups have welcomed Historic Scotland's intervention, the decision was attacked by Labour's tourism and heritage spokesman Lewis MacDonald, who said more checks should have been carried out before taxpayers' cash was spent on the project.
The MSP said: "I'm surprised that money was spent from the public purse without first checking whether it could be recovered. Surely there should have been efforts to see if the owner was in a position to pay for the work.
He added: "I don't understand why efforts aren't being made to recover the money from the owner's estate, even though no will was made. There should still be a claim made on the estate for in excess of 60,000 of taxpayers' money."
De Buar, who took his French wife's name, replacing his original surname, Elizavetin, became one of Moscow's most high-profile art collectors in the 1980s and quickly gained a reputation for lavish tastes.In all, he married six times, fathered several children, and bought Skelbo Castle, which was captured by Robert the Bruce's forces in 1308 and later became a Jacobite stronghold before falling into ruin.
Despite it being a shell with only the walls still standing, De Buar bought Skelbo, which has a ruined 17th-century house nearby, from adventure writer and Colditz survivor Michael Alexander for 75,000 in 1996.
With his new-found wealth, he also purchased a home in the south of France and a dacha in his home country. But it is widely believed he bought Skelbo and its surrounding estate for the title of baron, a fashionable trend which became increasingly popular among wealthy Russians in the 1990s.
Local heritage bodies have unsuccessfully attempted to contact De Buar for around a decade to carry out maintenance work on the crumbling castle. But Historic Scotland decided to act after the harshest winter in almost half a century caused the building to deteriorate rapidly. Builders were hired to erect scaffolding to stabilise the ruin.
Robin Ashby, 68, a retired lecturer and secretary of the Dornoch Heritage Society, said local residents are pleased that Historic Scotland carried out vital work following the savage winter, but said that the strange chapter of Mikhail de Buar is not yet over.
He said: "We've been campaigning for the castle to be restored for years so we are delighted that Historic Scotland have stepped in. I don't think any of us expected them to get the money back, as we have been trying to contact de Buar through his German lawyers for many years."
The court in Moscow are currently dealing with multiple claims for his fortune, the value of which is believed to be far higher, but has never been revealed.
Along with his extensive art collection, de Buar reportedly had assets in construction, and owned seven per cent of the oil giant Evikhon until 2000. He is believed to have visited Skelbo only once, in that year.Historic Scotland confirmed that it was not aware of the death of de Buar until June and have now contacted the British embassy in Moscow for advice on the legal situation.
A spokeswoman for the agency said: "Historic Scotland was sad to hear that the owner had passed away and that his estate is now subject to the Russian court.
"We are unable to apply for costs against the estate for the emergency stabilisation work we carried out for the urgent stabilisation of the castle.
"However, we would very much like to work with the new owner in order to preserve this 14th-century castle which has played an important role in Scotland's history."