In the action, the former clients alleged funds were missing and that the values of some investments were overstated, which meant the Mounts had claimed fees they were not entitled to.
As well as this, they accused the Mounts of keeping the proceeds of some investments for their own personal benefit.
The investors filed for summary judgment against the Mounts and their company, which was heard in the High Court at Nelson in 2013.In his decision on the matter, Associate Judge John Matthews found the Mounts had breached their duties, including to act honestly in their dealings with the clients and not defalcate their money. He was also satisfied that, as a consequence, the clients had suffered losses.
He entered judgment in the clients' favour for close to $3 million, with interest, which brought the total award to over $4 million.
The Mounts failed to challenge the decision at the Court of Appeal, and only reduced the amount awarded against them by close to $55,000.While they then attempted to take the case to the Supreme Court, the Mounts were denied leave to appeal by Justices William Young, Terence Arnold and Mark O'Regan on Friday.
"We see no issue of general importance in the proposed appeal and no appearance of a miscarriage of justice," the trio said.
The couple's $900,000 former home has already been sold to satisfy the High Court judgment and the proceeds shared among the former clients.
The group's lawyer, Rick Farr, today would not reveal how many cents in the dollar they had got back.
In a separate decision, the Court of Appeal last month turned down Mount's attempts to overturn his convictions.
Mount had argued he did not have a fair trial because he represented himself and was not given sufficient assistance. The three appellate judges disagreed and said they were satisfied the defence was adequately conducted without the assistance of a lawyer.
They dismissed the appeal but reduced Mount's sentence by nine months to six years' jail.