A site with two principal investigators?

We are working with a site that will participate in a clinical trial and the investigators have proposed to work with two principal investigators, instead of a single one. This has raised a lot of debate in our team, we are not sure if it is acceptable from a regulatory point of view. And if so, we would like to know what it implies in terms of ICH compliance as we can imagine that both PIs might need to divide their responsibilities and leave some register of this agreement.
Thanks in advance for your views.

Regulatory guidelines (ICH-GCP, FDA/EMA) require one Principal Investigator per site who is ultimately responsible for the trial. You can have two investigators working closely, but only one can be the official PI. The other should be a Sub-Investigator with delegated tasks documented in the site delegation log. This keeps accountability clear and compliant.