Deleting dashboards not shared with Admin User Not Working

Hello,

As an admin user, when I try to delete dashboards with REST API that are not owned by me or shared with me I receive the error below ( dashboard id as {dashboardId}):

{
"succeded": [],
"failed": [
{
"oid": "{dashboardId}",
"error": "Dashboard with id '{dashboardId}' not found.",
"status": 404,
"code": 10001
}
]
}

I can access these dashboards when I am in admin mode: /adminAccess?filters=all but the dashboard can't be deleted via REST API. 

How can I delete multiple dashboards with REST API that are not owned by me or shared with me?

Thank you