Section 21.11 - Conduct of investigations(a)Periodic compliance reviews. The Secretary shall from time to time review the practices of recipients to determine whether they are complying with this part.(b)Complaints. Any person who believes that he or she, or any specific class of persons, has been subjected to discrimination prohibited by this part may by himself or herself, or by a representative, file with the Secretary a written complaint. A complaint must be filed not later than 180 days after the date of the alleged discrimination, unless the time for filing is extended by the Secretary.(c)Investigations. The Secretary will make a prompt investigation whenever a compliance review, report, complaint, or any other information indicates a possible failure to comply with this part. The investigation will include, where appropriate, a review of the pertinent practices and policies of the recipient, the circumstances under which the possible noncompliance with this part occurred, and other factors relevant to a determination as to whether the recipient has failed to comply with this part.(d)Resolution of matters.(1) If an investigation pursuant to paragraph (c) of this section indicates a failure to comply with this part, the Secretary will so inform the recipient and the matter will be resolved by informal means whenever possible. If it has been determined that the matter cannot be resolved by informal means, action will be taken as provided for in § 21.13 .(2) If an investigation does not warrant action pursuant to paragraph (d)(1) of this section the Secretary will so inform the recipient and the complainant, if any, in writing.(e)Intimidatory or retaliatory acts prohibited. No recipient or other person shall intimidate, threaten, coerce, or discriminate against any individual for the purpose of interfering with any right or privilege secured by section 601 of the Act or this part, or because he has made a complaint, testified, assisted, or participated in any manner in an investigation, proceeding, or hearing under this part. The identity of complainants shall be kept confidential except to the extent necessary to carry out the purposes of this part, including the conduct of any investigation, hearing, or judicial proceeding arising thereunder.