KwaZulu-Natal Road Traffic Inspectorate spokeswoman Zinhle Mngomezulu said the tanker transporting diesel overturned near the Ultra City service station spilling thousands of titres of diesel.
Vehicles travelling towards Johannesburg on the N3 were re-routed from the N3 via the R103, as authorities closed off the highway to traffic and attempted to clean up the spill.
Mngomezulu said it was not immediately clear when the N3 north-bound would reopen to traffic.
Fortunately noone was injured in the accident and the cause of the accident is unknown. Authorities were on the scene to investigate, and investigations continue.