Players expressed shock, surprise and a sense of betrayal at the news the PGA and DP World Tours were merging their commercial operations with the Saudi-backed LIV Golf series.

More than a year of contention and litigation between LIV and the established Tours and the players who joined the new competition ended in the most astonishing and abrupt fashion on Tuesday with the announcement that the three bodies had set up a new commercial entity to “unify golf”.

One American player, Wesley Bryan, replied to the PGA Tour tweet confirming the merger by writing: “Love finding out info on Twitter. This is amazing. Y’all should be ashamed and have a lot of questions to answer.

“I feel betrayed, and will not not be able to trust anyone within the corporate structure of the PGA TOUR for a very long time.”

The move came as a huge surprise to many professionals, with Canadian Mackenzie Hughes tweeting: “Nothing like finding out through Twitter that we’re merging with a tour that we said we’d never do that with.”

Fellow pro Ben An wrote: “I’m guessing the LIV teams were struggling to get sponsors and PGA Tour couldn’t turn down the money.

“Win-win for both tours but it’s a big lose for who defended the tour for last two years.”

Six-time Major winner Phil Mickelson, one of the players who joined LIV Golf, described the merger as “awesome news”.

The new entity will be powered by Saudi Arabia’s financial muscle, with the statement confirming the merger saying that the Middle Eastern country’s Public Investment Fund (PIF) would “make a capital investment into the new entity to facilitate its growth and success”.

The PIF would also have the exclusive right to further invest in the commercial entity, the statement said.

Amnesty International expressed concern at what it saw as a further attempt by Saudi Arabia to launder its human rights record through the vehicle of sport.

“While this may have taken some golf fans and commentators by surprise, it’s really just more evidence of the onward march of Saudi sportswashing,” Amnesty UK’s Felix Jakens said.

“It’s been clear for some time that Saudi Arabia was prepared to use vast amounts of money to muscle its way into top-tier golf – just part of a wider effort to become a major sporting power and to try to distract attention from the country’s atrocious human rights record.”

And the 9/11 Families United group said it was “shocked and deeply offended” by the merger.

“Saudi operatives played a role in the 9/11 terrorist attacks, and now it is bankrolling all of professional golf,” the group said in a statement.

R&A chief executive Martin Slumbers welcomed the news of the agreement, writing in a statement: “We care deeply about golf’s future and are committed to ensuring that the sport continues to thrive for many years to come.

“This agreement represents a huge step toward achieving that goal for golf and we look forward to working with the new entity for the benefit of the sport globally.”