Hartlepool man Marty Booth was initially given first place in the prestigious Paul Roggeman European Open Beach Championship, which was held on the Yorkshire coast.
The three-day championship was held between Spurn Point and Bridlington, East Yorkshire, from February 15.
The event was organised by East Riding District Council and an investigation was launched after judges received information of wrongdoing.
More than 1,000 anglers took part in the competition.
The second place angler Chris Fisher, from Aldbrough in East Riding of Yorkshire, was named winner after Booth was disqualified.
A post on the Paul Roggeman European Open Beach Championship Facebook page said: "Following the conclusion of the 2019 Paul Roggeman European Open Beach Championships and after an ongoing investigation, a decision has been made to disqualify a competitor which has changed this year's results.
"The updated results can be found on our website. As the organisers, East Riding of Yorkshire Council takes any breach of competitor rules very seriously. Our aim is to deliver a fair, honest and open event that can be enjoyed by all competitors and the council will not tolerate anyone bringing the reputation of the event into disrepute.
"We would like to take this opportunity to congratulate Chris Fisher from Aldbrough, the winner of the Paul Roggeman European Open Beach Championships 2019.
"Please note as this announcement has been made this morning, the next issue of Sea Angler has already gone to press, so will not have the up to date results.
"Thank you to everyone that took part in the championships, the dates for 2020 will be announced shortly."
Competition sponsor welcomed the commend the organisers for their swift action.
A post on the Anyfish Anywhere Facebook page said: "Anyfish Anywhere has been a proud sponsor and supporter of the European Open Beach Championships for well over ten years. Working initially with Paul Roggeman and now Will Hall, we have seen the competition grow year on year into the hugely prestigious international event that it is today.
"After the conclusion of this years EOBC, East Riding District Council disqualified one of this years competitors for a breach of competition rules.
"Anyfish Anywhere would like to take this opportunity to commend the council on its swift and decisive action and would like to pledge our ongoing support to the EOBC for 2020 and beyond.
"We would also like to take this opportunity to congratulate Chris Fisher from Aldbrough, the winner of the Paul Roggeman European Open Beach Championships 2019."