Nevil Maskelyne wanted to claim the longitude prize money for himself. He was on the Board of Longitude committee that awarded the money so there was a classic conflict of interest. Chronometer maker Harrison had to appeal to the King and was given the money by Parliament not the Board of Longitude. " The results of the voyage were made public at a meeting of the Board of Longitude in early 1765, where it was disclosed that Harrison's chronometer had produced Bridgetown's longitude with an error of less than ten miles after a sea voyage of more than 5,000 miles. Maskelyne's method on the other hand showed an error of 30 miles."
http://en.wikipedia.org/wiki/Nevil_Maskelyne