If a public sector agency collects personal information from an individual, the agency must take such steps as are reasonable in the circumstances (having regard to the purposes for which the information is collected) to ensure that--
(a) the information collected is relevant to that purpose, is not excessive, and is accurate, up to date and complete, and
(b) the collection of the information does not intrude to an unreasonable extent on the personal affairs of the individual to whom the information relates.