An RAF search and rescue helicopter and three RNLI lifeboats are searching off the coast of Harwich after getting reports that two people had come off a ferry.
Then RNLI says it happened about a mile off the Harwich coast, as the ferry was heading outbound.
Also helping in the search are tug boats and other vessels that were in the area at the time.
It happened just before 10am this morning.
More top news
A community in Luton is in shock after a local woman was killed in what's believed to have been a burglary that went wrong.
One of our train operators is stopping staff from clipping train tickets for fear they will hurt their wrists.
Mist and low cloud as well as drizzle will affect many parts of the East of England tonight, especially to the north. Brighter tomorrow.