The families in Blackburn, West Lothian, have been told by developer Crannog, which acquired the land on which four houses had been mistakenly built, that it has been forced to surrender ownership to its private backers.
These backers hold a charge over the land on Happy Valley Road and are allegedly owed £800,000.
The financiers, according to Crannog's director Jack Anderson, will take possession and "will not offer the land for sale again" unless the Law Society of Scotland's indemnity insurers step in immediately to buy it.
Crannog collapsed after it ran out of money to continue Court of Session actions for eviction of the four families from their homes.
Mr Anderson says he embarked on the actions on legal advice in an attempt to force a settlement, after private negotiations with insurers Royal and Sunalliance to sell the land broke down.
But RSA then stepped in to defend the families against Crannog's actions, with its Edinburgh-based law firm Simpson & Marwick binding the families to strict conditions of secrecy as to the insurer's involvement.
RSA, the principal insurer for the Law Society of Scotland's master policy which indemnifies law firms against claims for negligence, had in 2006 defended Court of Session actions for negligence brought by the families, refusing to accept liability.
Those actions were then sisted (permanently suspended) as a condition of RSA's secret defence of the families against Crannog.
But despite having forced Crannog out of business, RSA is now being asked to buy the land again by that company's backers, who appear to have taken an uncompromising stance.
Mr Anderson has written to the four families: "The only way to prevent the charge holders from taking possession will be for the insurers to meet their obligations immediately. Given their tactics to date this will not happen. Possession by the charge holders of the land will occur over the month of May.
The charge holders make it very clear that they will not offer the land for sale again."
Ian Reid, one of the householders, who felt unable to speak out last year due to the conditions imposed by Royal and Sunalliance, said he felt matters had now reached a desperate pass. Mr Reid said this week: "Instead of Crannog owning the land it is two guys who are very wealthy and who are prepared to sit on that land forever and a day.
"That doesn't bode well for us, People can't sort out their affairs, they can't leave their house to anyone, can't do extensions, at this rate it is never going to be resolved."
Mr Reid has appealed to RSA's new chief executive Stephen Hester to intervene in the crisis, and he has recently been told that the company's representatives in Scotland will investigate.
The problem arose because of inaccurate mapping in the conveyancing of land from a local farmer to Braid Homes in 1999, and then mistakes in the construction phase before Braid Homes went bust.
Mr Anderson, in his letter to the families, says: "We negotiated purchase of the original unaffected site from Braid Homes which effectively lay abandoned. This allowed full completion of all works to the development . We were aware that there was an issue with the land as a consequence of conveyancing error. Equally, we understand that your solicitor and Royal Sun Alliance had also known of this for at least two years prior to our involvement. Our advice was that RSA would accept their responsibilities and agree reasonable compensation."
Royal and Sunalliance told The Herald last year: "The matter is the subject of ongoing litigation and as such we are unable to comment on the litigations themselves or on the disputes at the heart of the litigations." RSA declined to comment this week.
Earlier this year we reported on a second case in Aberdeen, where TV designer Sinclair Brebner has been waiting 11 years for valid titles to his flat worth over £300,000, and now faces eviction by a trustee acting for the estate of the businessman who sold it to him.
The trustee, Ewen Alexander of Johnston Carmichael, has said that while he sympathises with those affected it is "clearly a matter between them and the advisers who acted for them at the time of purchase"
An action against those solicitors, Esslemont Cameron Gauld now Ledingham Chalmers, might have triggered a claim on the profession's master policy, but no action has ever been taken. Mr Brebner is now represented by Balfour & Manson, who said: "The evidence suggests that the claim is properly directed to solicitors who were dealing with the property long before Mr Brebner and his purchasing solicitors became involved."
The cases have prompted Jenny Marra MSP to table a motion in the Scottish Parliament raising all the issues uncovered by The Herald, with the intention of a full debate at Holyrood.