Police and ambulance crews have reportedly raced to the London station. London & UK crime tweeted: “Reports of major incident happened at Chadwell Heath station, lots of ambulances and police cars on scene.”
National Rail issued an update shortly after 4.30pm and said a passenger has been taken ill at the station.
Routes between Shenfield and London Liverpool Street are affected and the train operator warned some services may be cancelled.
Passengers can expect disruption to their journeys until at least 6.00pm.
In an update National Rail says: “A passenger being taken ill at Chadwell Heath means trains running through this station may be cancelled or revised.”
This is a developing news story, more to follow.