the said person; the person in question
Formal written term used in documents, reports, or legal contexts to refer to a previously mentioned person. Not used in casual speech.
The said person denies any involvement in this matter.
Please refer to the attached sheet for the background of the person in question.
Compound of 該 (the relevant, the said) and 氏 (honorific suffix for a person). The reading がいし follows the on'yomi of both characters.