A prized painting by American artist Winslow Homer may be one of four works to be sold by the Delaware Art Museum in order to replenish its endowment and pay off debt.

The iconic "Milking Time," Homer's 1875 image of a milkmaid and child overlooking cows in a pasture, disappeared from the museum's online collections database, reported the News Journal on Saturday. Museum officials did not confirm a sale of the Homer and say they will not disclose the works to be sold in order to protect their value on the market.

When asked about the Homer, museum CEO Mike Miller said, "You can make your own speculations." He says that "Milking Time" was purchased in 1967 using a bank loan and donations from the group Friends of Art.

The Association of Art Museum Directors strongly opposes the sale of artworks from the museum's collections. AAMD president Timothy Rub, who also heads the Philadelphia Museum of Art, alerted the public about the Homer's removal from the Delaware Museum's database.

Experts consider Homer's "Milking Time" to be a "landmark painting" for the 19th century artist. Its value is hard to pinpoint since few of  Homer's major works have come to market recently. In 1998, Homer's 1885 painting "Lost on the Grand Banks" reportedly sold for $30 million in a private sale to Microsoft chairman Bill Gates. 

Delaware Museum announced in March that it would sell four works from its collections with the hope of generating $30 million to cover a $19.8 million bond debt and secure the furture of the museum with endowment funds.