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.
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Starting cold and dry Boxing Day. Wet and windy later.
The Met Office has issued a yellow cold weather alert and there's the risk of snow in places later on Boxing Day.
Mostly dry and bright, but chilly. Frost tonight.