Police are investigating a possible turf war involving Morecambe Bay cockle gangs - after scores of workers were left stranded off the coast.
Liverpool Coastguard had to shepherd at least 144 cocklers to safety when two tractors crashed four miles off-shore at Newbiggin on Saturday.
Cumbria Police are now probing the possibility the incident was caused by gang rivalry.
Safety officials are also talking to the gangmasters.
RNLI hovercraft, RAF rescue helicopters and inshore lifeboats were called to help with the rescue mission on Saturday.
A group of 60 Scottish cocklers and another team of 76 Chinese cocklers were led to safety.
Liverpool Coastguard confirmed 144 cockle pickers were rescued, and said reports that that figure could be as high as 192 could not be confirmed.
At least 21 Chinese cockle pickers were killed just a few miles away near Hest Bank in February after they became stuck as the tide came in.
Police said in July they were investigating claims that a turf war had broken out between gangs.
Janet Butler, from Newbiggin, who runs a shellfish business, said she believed the latest rescue mission began after a clash between groups of workers.
She said: "All I know is that there was some sort of altercation between the gangmasters who run the Chinese cockle gangs and the Scots.
"There was a clash and then somehow the tractors have collided. It is not the first time we have seen this sort of thing happen.
"These people have come onto our cockle beds and all they are interested in is making as much money as possible.
"They have no respect for the local ecology or even the lives of the people who are working for them."
Mark Clark, from the Maritime and Coastguard Agency, said it was the 16th operation launched this year to rescue stranded cocklers in the area.
"If something like this happened at high tide in failing light, on a winter's day we could have a rerun of what happened in February, with fatalities."
The incident has prompted renewed calls for greater regulation of the cockle-picking industry.
Geraldine Smith, Labour MP for Morecambe and Lunesdale, said: "I want a proper licensing system put in place for people working in the Bay.
"North West and North Wales Sea Fisheries tell me they can only introduce such a scheme on fisheries conservation grounds - in other words they could introduce one if cockles were in danger, but not if people's lives are in danger."