Grand Prix jumper Good Guinness.
Trainer Patrick Seaton told Horsetalk the horse, Good Guinness, had only just been located and was in the process of being picked up.
"We have just found him," he said of the Irish Sport Horse. "I got a couple of calls this morning. Someone had recognised him through the [electronic] fliers we put out. It just shows what a powerful thing the internet is."
The finding of Good Guinness, who won three grand prix events last year and is probably worth around $US200,000, solves a mystery that has been fermenting for a week.
Good Guinness had been shipped by road across the United States from California in the middle of last September to an East Coast property, with the intention of marketing him for sale from there.
The horse that turned up at Frank Madden's New York farm six days later - on September 14 - was not Good Guinness. Madden had not seen Good Guinness before, but its dark brown colouring and markings matched Good Guinness's documentation.
It wasn't until Seaton returned from Europe and paid a visit to the East Coast a week ago to see Good Guinness competing in Wellington, Florida, that he realised it wasn't the same horse.
Closer investigation showed the Good Guinness substitute had a leg scar and two missing front teeth.
It had also been noticed that the substitute simply wasn't performing up to the standard of a grand prix horse.
Meanwhile, in New Jersey, the real Good Guinness was competing well in low to junior level junior events.
"He was champion for both weeks that he showed."
Seaton told Horsetalk he was delighted to know Good Guinness was safe.
"It was my birthday yesterday and someone asked me what I wanted. I said I wanted my horse back."
Seaton, who does not own Good Guinness but trains him, said he had ridden the horse for about three to four years.
Good Guinness was competing in New Jersey until the name Kanye.
Seaton said he did not want to say too much at this stage, as the circumstances surrounding what happened are still being explored.
However, it appears that the people competing Good Guinness as Kanye had been leasing him since September and had not been familiar with the horse before its arrival. It appears the horse that turned up at Madden's property in New York may be Kanye.
There remained some mysterious circumstances that he hoped would be resolved once further inquiries were made, Seaton said, adding that his first priority was to get Good Guinness back in his care in California.
He said the recovery of the horse has come as a great relief. "I am exhausted now that the adrenalin had worn off."
Seaton confessed that he thought it odd that Good Guinness had not been meeting expectations on the East Coast.
"The most important thing is that we found the horse."