A British man who spent 7 1/2 years working on a jigsaw puzzle said he finally completed the task but was unable to locate a missing piece.

Jack Harris, 86, of Shepton Mallet, England, said he began the puzzle, a gift from his daughter-in-law, in 2002 and discovered after assembling 4,999 pieces that one was missing, The Daily Telegraph reported Monday.

Harris said he frequently received puzzles as Christmas presents and the 5-foot-long behemoth of a puzzle was given to him after he boasted about how quickly he could finish.

"I always said I could get the puzzles done by the end of March so I could get out into the garden, but this one took a bit longer," Harris said.

He and his family said the piece may have been accidentally thrown out or eaten by a family dog.

Harris said a spokesman for Falcon Games LTD, which created the puzzle version of James Tissot's "The Return of the Prodigal Son," told him the puzzle is no longer being produced and spare pieces are not available.