As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT DIVERTED TO LHR FOR REPORTED ODOR IN THE COCKPIT; THE ODOR DID NOT DISSIPATE. EMERGENCY WAS DECLARED. MAINTENANCE FOUND THE FLIGHT DECK DOOR LOCK CIRCUIT BREAKER POPPED. RESET AND POPPED AGAIN WITH THE SAME SMELL. REMOVED AND REPLACED FLT DECK DOOR LOCK IAW AMM 52-51-02. OPS CHECK GOOD.