The Court of Appeal on Wednesday upheld a decision of High Court Judge Vinodh Coomaraswamy dismissing their claims.
Justice Coomaraswamy found that the minority owners have had their day in court, been awarded the appropriate costs, and are therefore precluded from bringing a separate action to recover their unrecovered legal costs.
The minority owners, Mr Then Khek Koon, his wife Jasmine Tan, Mr Rudy Darmawan, his wife Widia Seteono and Mr Darmawan's aunt Maryani Sadeli, were earlier awarded $354,370 by the Court of Appeal in a separate action after it blocked the sale.
But that was not all they had asked for, leaving a gap between what they recovered and what they had to pay their lawyers.
The minority owners went back to court in 2012 to argue that Mr Arjun Samtani, chairman of the first sales committee, and committee member Tan Kah Gee, were obliged to compensate them for unrecovered costs. Both were named as prime movers of the sale by the Court of Appeal in a 2009 ruling that disallowed the deal.
But Justice Coomaraswamy found that the owners were precluded from bringing their claim for costs as damages.
Appealing against his ruling, the minority owners argued that they were not "seeking a windfall, (but) simply seeking to be made whole as regards their losses which stem from (Mr Samtani and Mr Tan's) wrongdoings".
But the Court of Appeal dismissed their appeal this week and awarded Mr Samtani and Mr Tan each $30,000 as costs of the appeal.
They had contended that the minority owners' claim was unsustainable since costs had already been determined by the Court of Appeal.
In asking for the minority owners' claim to be dismissed, Mr Tan described them as "not victims, but insatiable opportunists who, having benefited from the setting aside of the collective sale as well as recovered standard costs, want even more than what they rightfully deserve".
The legal spat over Horizon Towers began in early 2007.
The $500 million that Hotel Properties had offered for Horizon Towers in January 2007 was, at that time, the highest price paid for an en-bloc sale in Singapore.
But when the property market started rising in early 2007, the minority owners contested the sale, saying the price was too low. They fought all the way to the Court of Appeal which eventually killed the sale in 2009.
By then, the courtroom battle had lasted 21/2 years and was estimated to have cost up to $4 million in lawyers' fees.