Glanmore Property Fund, registered in Guernsey and run by Tilney Asset Management, raced from £25m of assets in 2000 to £1.2bn in 2007, when gearing was said to be almost 50%.
The fund, which holds UK regional office, industrial and retail property including 10% in Scotland, was last valued at £303m, above its remaining debt following asset sales.
Urbicus was created in 2011 by Edinburgh merchant banker Ben Thomson, the former chief executive of Noble Group, and property entrepreneur Mark Shaw, whose Hazeldene group built the £75m iQ development in Aberdeen.
Its backers are known only to include the New York hedge fund Elliott Associates, run by billionaire investor Paul Singer.
Urbicus has kept a low profile since it was revealed two years ago to have bought the £300m Scottish property portfolio of the collapsed Anglo-Irish Bank, which included debt such as that used for the Dakota Hotel on the M8. It was put up for sale early in 2012.
Urbicus made no announcement yesterday.
However, responding to a report in 'Property Week', a spokesman said: "We can confirm that Urbicus, with the backing of a number of investors, has acquired the debt of Glanmore Property Fund, and is now acting as lender to the fund."
Mr Thomson also chairs boutique investor Inver- leith Capital, the National Galleries of Scotland, and DevoPlus.
Glanmore, one of the few unlisted funds in the sector to woo small investors, was one of the early indicators of the property crash when in December 2007 it imposed a six-month delay on redemptions. According to its website, that delay is currently "72 months".
The purchase price of the fund is down by 98% over five years, against a 25% overall gain for the property sector, and down by 40% in 2013 when the sector is up 6%, according to figures from Trustnet.
Now advised by CBRE, the fund has already put up for sale a portfolio of 15 assets known as the Tiger Portfolio for £80m, the proceeds of which will be used to pay down the debt.
The Urbicus spokesman said: "The fund continues to operate as before. Preparations for Tiger were put in place by the fund prior to Urbicus becoming the lender."
Urbicus, where former Anglo-Irish executive Marcus Rennie is operations director, is backing Glanmore's belief in a growing investor appetite for secondary property in the UK regions.
Mr Shaw last year bought over an Italian ski resort built for the Winter Olympics in 2006 and funded by Anglo-Irish. He is an active member of the First Minister's pro-independence campaign team.