Should a hiring manager seek information about an internal candidate from their current line manager?

Subject to the candidate's agreement, the hiring manager could seek information from their current line manager. The most relevant information is objective performance-based information. Information based on the manager's opinion or the employee's reputation may be inaccurate or irrelevant. The hiring manager may not be able to obtain the same sort of information on external candidates, which could create an unfair advantage or disadvantage for the internal candidate. Information from referees should be only one of the factors that hiring managers take into account within a thorough internal assessment process and they should treat the information with caution.