A Saudi Arabian-backed consortium has ended its bid to buy Newcastle United.
The group, which included Saudi Arabia's sovereign wealth fund PIF, PCP Capital Partners and Reuben Brothers, had agreed a £300m deal to buy the club from Mike Ashley in April.
The deal was still being scrutinised under the Premier League's owners' and directors' test and it is understood PIF ran out of patience.
The consortium said that it was with "regret" that it had pulled out.
Amanda Staveley, the British businesswoman behind PCP Partners, said she was upset for the club's supporters.
"It's awful," she said, adding that there would have been huge investment in the area.
"We are devastated for the fans. We really thank the fans - I personally thank them for all their support."
A statement from the investor group said: "As an autonomous and purely commercial investor, our focus was on building long-term value for the club, its fans and the community as we remained committed to collaboration, practicality and proactivity through a difficult period of global uncertainty and significant challenges for the fans and the club.
"Ultimately, during the unforeseeably prolonged process, the commercial agreement between the Investment Group and the club's owners expired and our investment thesis could not be sustained."
The consortium's withdrawal could pave the way for a takeover by American entrepreneur Henry Mauriss, who has registered his interest in Newcastle and remains extremely keen for the acquisition to happen.
What led to a delay after the takeover was agreed?
As revealed by the BBC this week, the Premier League was seeking clarification of the links between PIF and the Saudi state.
PIF's chairman is Crown Prince Mohammed bin Salman, and it appears the Premier League's lawyers had been struggling to establish the precise links between the consortium and the Saudi government.
The Premier League declined to comment.
But its rules meant it wanted to know who would have control, where funding would come from, and who would appoint the board.
It is understood that it could not be sure where responsibility would lie.
What's been the reaction to the situation?
Human rights groups and the fiancee of murdered journalist Jamal Khashoggi, Hatice Cengiz, had opposed the takeover.
"Let this defeat send a strong message to the leadership in Saudi Arabia that they will not be able to use their money to cover up their human rights record or protect those responsible for Jamal's murder," Cengiz said.
"We will not stop and we will not rest until we get justice for Jamal."
Speaking after the investor group's withdrawal, Peter Frankental, Amnesty International UK's economic affairs programme director, claimed the bid had been an attempt by the Saudi Arabia government to "sportswash" their human rights record.
"The fact that this sportswashing bid has failed will be seen by human rights defenders in Saudi Arabia as a sign that their suffering has not been entirely overlooked," he said.
In June, Premier League chief executive Richard Masters said he would "fully consider" calls for the proposed bid to be blocked.
Newcastle MP Chi Onwurah tweeted: "I know that many constituents will be disappointed and frustrated by the withdrawal of the latest Newcastle takeover offer.
"I will be writing to the Premier League to ask why they took so long and gave so little clarity to Newcastle fans."
One of the issues raised by critics of the takeover was Saudi Arabia's response to cases of unauthorised broadcasting of Premier League games in the country.
In June, the World Trade Organization issued a report which found representatives of the Saudi state had facilitated the breach of international piracy laws via the TV network beoutQ.
Saudi Arabia has always denied aiding the beoutQ operation and has insisted there is no link between its government and the alleged piracy.
BBC sports editor Dan Roan:
Arguably the most controversial takeover deal in Premier League history is finally over.
Sources close to the consortium say they tried to prove to the Premier League that the Saudi government would have no say in the day-to-day running of the club.
The Premier League seems to have been concerned that individuals not on the club's new board would have had influence over decision-making at St James' Park because the Saudi Crown Prince is the chairman of PIF. Ultimately this issue could not be resolved.
Current owner Mike Ashley is also understood to have tried to renegotiate the deal in recent days because of the length of time that had lapsed, and that also contributed to the decision by the group to walk away.
But with so many negative headlines over Saudi Arabia's poor human rights record - plus tension with rival clubs and broadcast partner beIN Sport over television rights piracy concerns - Premier League officials may be privately relieved the consortium has taken the decision out of its hands.
Many in football will now want to see its Owners and Directors' Test strengthened to ensure states like Saudi Arabia cannot buy clubs, and there is no repeat of a saga that has done little for the game's reputation.
After months of uncertainty, however, Newcastle United fans desperate to see the back of Ashley will no doubt see it very differently.