Dumped oil painting fetches $1m
It was found by Elizabeth Gibson as she took her morning walk four years ago on Manhattan's Upper West Side.
After discovering the painting's value, she returned it to its original owner.
It sold for $1,049,000 (£507,900) to a telephone bidder at Sotheby's New York auction house.
Sotheby's describes the painting as an important work from Rufino Tamayo's mature period.
Elizabeth Gibson said she was drawn to the painting when she spotted it on the street.
"I know nothing of modern art but it didn't seem right for any piece of art to be discarded like that," she said.
It hung on a wall in her home for several months before a friend suggested it might be valuable.
An internet search revealed that the missing painting had been the subject of an appeal for information on the Antiques Roadshow TV programme.
Ms Gibson has already received a $15,000 reward the couple put up when it was stolen, plus an undisclosed percentage of the sale of the painting.
It is still not known how the painting ended up on the street.
The owners - a couple from Houston whose names have not been disclosed - bought the oil on canvas, with marble dust and sand worked into the paint, in 1977 at Sotheby's.
August Uribe, Sotheby's senior vice-president of impressionist and modern art, said that the husband had paid $55,000 for it as a gift for his wife. The husband later died.
At the time of the theft in 1987, the couple alerted local and federal authorities.
Information on the painting was posted on the databases of the International Foundation for Art Research, and the Art Loss Register.
The FBI is still investigating the theft.
"Forgive me Father for I have sinned"
Father **** to confessioner:
"Go on my son, the Boston Vermeer, yes, yes, now what about Rembrandt's Storm on the Sea of Galilee, OK my son."
Hello, is that the Garda/Police/Boston Police Department?,
"This is Father *****, I have found the stolen Gardner art in one of my confession boxes and would like to return them forthwith, oh yes, and claim the reward."
"That's the only way to do it !"