Mr McGeever (68), who was found wandering at the side of a rural road on Tuesday, has told gardai that he was taken eight months ago by armed men, but he cannot recall what happened after that.
During the boom times, he ran a successful property business selling luxury homes in Dubai to wealthy Irish and British clients.
And he showed all the trappings of wealth with a stunning mansion, a helicopter and a fleet of top-of-the-range vehicles at his disposal.
Mr McGeever was discovered in a dishevelled state near Ballinamore, Co Leitrim, on Tuesday night and he had lost about five stone in weight.
The businessman told gardai that he was abducted by three masked men at gunpoint from the garden of his mansion home at Craughwell, Co Galway, last May.
He said that the kidnappers had demanded a ransom for his safe release, but he did not know whether a ransom had been paid.
Mr McGeever said he could not remember what had happened to him in the meantime, but as he was being released, he was given a mobile phone and warned to keep it with him.
Gardai said he was feeble and thin when he was found and apart from the weight loss, he had a lengthy beard and very long fingernails.
The marking on his forehead was thought to have been cut into him with a knife.
The developer, who fronted KMM Commercial Properties, built one of the largest mansions the Celtic Tiger era witnessed in the small Galway town of Craughwell.
The lavish property was christened 'Nirvana' and during the boom was estimated to be worth well over €3m.
Two security gates with stained glass features decorate the entrance of the mansion, which is surrounded by immaculately groomed lawns. It has a water fountain at the front.
Originally from Swinford, Co Mayo, locals in the area were used to seeing Mr McGeever driving his JT22 Porshe.
His initials "KMM" were branded across an EC120 Eurocopter in which he travelled the country.
When not taking to the air, he had a fleet of high range vehicles to use, often with personalised number plates, including two H2 Hummers.
All his vehicles were kept immaculately and were shown off each year at the All-American Car Show in Kilbeggan.
A couple spotted him in the middle of the road on Tuesday night and brought him to Ballinamore Garda Station.
He was taken to Mulligar hospital where he was treated for malnutrition and dehydration.