The Goodwill is moored in St Helier harbour after the incident, which happened more than two hours before sunrise.
Jersey Coastguard has been coordinating the search and rescue operation.
‘There were three people on board the fishing vessel – the captain and two crew members,’ a spokesman confirmed.
‘Coastguards have deployed the RNLI’s inshore and all-weather lifeboats, two French rescue helicopters, Guernsey’s RNLI all-weather lifeboat and a French naval fixed-wing aircraft.
‘Also involved in the search are Channel Islands Air Search, Ports of Jersey’s pilot boat, and the Government of Jersey’s fisheries rib.
‘A large number of local fishing vessels have also been helping with the search, as well as drones, beach lifeguards on jet-skis, and honorary police officers.’
The vessel is believed to have sunk in about 40 metres of water, which will require specialist diving resources.
‘An offshore construction vessel currently working on the St Brieuc wind farm project, will be coming with one of its remote operation vehicles to confirm the location of the boat,’ the spokesman said.
‘Jersey Coastguard is continuing to coordinate the response, in conjunction with the States of Jersey police, the Government of Jersey, and other agencies.’
Condor Ferries said that the Goodwill had left St Peter Port for Jersey at 4.41am with five passengers and 24 crew on board.
Mr Napton said yesterday evening that he had been notified the search had been suspended for the night.
‘This is a very difficult situation and our thoughts are with the families and loved ones of these fellow seafarers as we all try to come to terms with what has happened,’ he said.
‘Condor is fully complying with the ongoing investigation which will establish the cause of this incident.’
The Jersey Fishermen’s Association had earlier provided a scan of the seabed which it said showed the boat on its side on the bottom, while debris was seen on the surface.
JFA president Don Thompson said there had been no sign of a life raft.
L’Ecume II is an 18-metre wooden trawler. The trawler’s skipper has been named in Jersey as Michael Michieli.
An exclusion zone has been placed around the collision site, following a ministerial decision from Economic Development Minister Deputy Kirsten Morel, which prevents the passage of any vessels, diving, fishing, laying static gear or trawling.