12. Where joint tenants or tenants in common

12. Where two or more persons are entitled to the possession of immovable property as joint tenants or tenants in common, one or more of them may maintain an action in respect of his or their undivided shares in the property in any case where such an action might be maintained by all. 

Section 12 of the code is intended to apply to a case of a mere trespasser and not to apply to a case where one co-owner excludes another co-owner from possession.

Arnolisa Vs. Dissan (4 N.L.R. 163) 

One co-owner can institute an action for damages caused to the common property without joining the other co-owners either as plaintiffs or defendants.

Rockland Distilleries Vs. Azeez (52 N.L.R. 490)