Article 33 International Covenant on Civil and Political Rights (ICCPR)

1. If, in the unanimous opinion of the other members, a member of the Committee has ceased to carry out his functions for any cause other than absence of a temporary character, the Chairman of the Committee shall notify the Secretary-General of the United Nations, who shall then declare the seat of that member to be vacant.

2. In the event of the death or the resignation of a member of the Committee, the Chairman shall immediately notify the Secretary-General of the United Nations, who shall declare the seat vacant from the date of death or the date on which the resignation takes effect.

See also: Article 32 ICCPR