1. An apparatus for detection of duplicate bug reports comprising: a receiver module configured to receive first bug report and a word matrix, wherein the word matrix comprises a ranked list of dissimilar duplicate words; an extractor module to extract at least one keyword from the first bug report for creating a first search string; a comparator module configured to compare each of the keywords from the first search string with the word matrix to identify the dissimilar duplicate words corresponding to the keywords; an expander module configured to expand the first search string by including the dissimilar duplicate words for creating a second search string; and a searcher module configured to search a bug report repository with the first search string for detecting similar duplicate bug reports and the second search string for detecting dissimilar duplicate bug reports.