Rod Henderson, head of coastal operations for the the Marine Management Organisation, said:
British boats are entitled to fish in the area, 20 miles north west of Le Havre, even though it is in French waters.
The area had recently been closed off to French vessels by local authorities but was reopened on October 1, the spokeswoman said. UK boats were still entitled to enter the waters during the "closure" period.
The MMO spokeswoman said one reason the closure could have been put in place was so scallop stock levels could be replenished.
The situation was eventually defused after the MMO contacted the French authorities, who intervened.
French fishermen have reportedly been pelting British boats with rocks and flares in a row over scallop fishing in the English Channel, the Marine Management Organisation (MMO) said today.
British fishermen reported the attacks to the MMO, which said an estimated 40 French vessels and eight UK vessels were involved in Monday's incident in scalloping grounds in the Bay de Seine.
A spokeswoman could not confirm whether the French fishermen were throwing rocks and flares, but said they had received reports from one of the UK vessels that this was the case.