A landlord can not consent to search. They can report suspicious circumstances that may give law enforcement probable cause, or enough info to obtain a warrant. I'm not taking any sides here, just reporting some court decisions regarding the matter.
http://www.caselaw4cops.net/searchandseizure/consent.htm
I don't know about your state, but here in California a landlord can enter a tenant's unit for several reasons (e.g. inspection, maintenance) with 24 hour prior notice,and can enter the property at any time in the case of an emergency. There is nothing preventing said landlord from entering with police officers in tow.