Nothing in this part shall be construed as limiting the power of removal of policemen vested in the board of police commissioners or police committee by the charter of any city, except that no member of the retired list shall be removed until he has had an opportunity to be heard in his own behalf before such board or committee. Such board or committee may, at its discretion, order any member on the retired list to be examined or reexamined by the surgeon of the department or by a board of surgeons to be designated by such board or committee, and, if such member is reported capable of performing duty, such board or committee may, by the affirmative vote of a majority of the whole number of its members, with the approval of the mayor, restore such member to either the regular or veteran reserve force and may, in like manner, transfer any member of the veteran reserve to the regular force.