A group led by Saudi Arabia’s sovereign investment fund completed its purchase of the Premier League soccer team Newcastle United on Thursday, moving swiftly to overcome objections to its yearslong pursuit of a place as an owner in one of the world’s most prominent sporting competitions.

The sale instantly transformed Newcastle, an underachieving club whose home in the north of England is far from the power centers of European soccer, into theoretically one of the richest teams in the world, backed by the wealth of Saudi Arabia’s Public Investment Fund, a vehicle that controls assets worth $500 billion.

But it also raised new questions about the economics and morality of allowing a nation state, and particularly one accused of serious human rights abuses, into the elite club of Premier League owners.

The announcement that the Saudi-led group had acquired full control of the club from its previous owner, the retail tycoon Mike Ashley, came days after Saudi Arabia resolved the obstacle that had blocked a similar agreement last year.

Since 2017, Saudi Arabia has not only blocked the Qatari sports network beIN Sports — one of the Premier League’s most lucrative broadcast partners — from operating within its territory, as part of a broader dispute between the two nations, but it has also been accused of both hosting and running a rogue network that pirated beIN’s content.

Last year, as the Saudi-led bid to take charge of Newcastle appeared to gather momentum, beIN Sports demanded the Premier League refuse to approve the takeover. Eventually, the Saudi consortium withdrew its offer before the Premier League had to make a definitive decision.

But while it emerged on Wednesday that Saudi Arabia had lifted its ban on beIN, the Premier League insisted that the resolution of the piracy issue was not the decisive factor in its permitting the takeover to go through.

Instead, the league said in a statement on Thursday that it could allow the deal to happen because it had received “legally binding assurances” that the Saudi state would not be in control of one of its member clubs.

The league’s statement suggested it is now apparently satisfied that the P.I.F. — chaired by Mohammed bin Salman, the crown prince of Saudi Arabia — is entirely separate from the Saudi state, where Salman is deputy prime minister, minister of defense and widely regarded as the country’s de facto ruler.

Yasir al-Rumayyan, the governor of the P.I.F., will serve as Newcastle’s nonexecutive chairman, with Amanda Staveley, a British businesswoman, and Jamie Reuben, a billionaire property investor, also sitting on the club’s newly constituted board.

All directors of Premier League clubs are subjected to a background check, designed to make sure they are suitable custodians of what are often beloved civic institutions.

A number of human rights organizations have made their objections to the deal plain, with Amnesty International calling on the Premier League to change the rules of its owners and directors’ test to ensure that those accused of human rights violations cannot take charge of soccer teams.

“Ever since this deal was first talked about we said it represented a clear attempt by the Saudi authorities to sportswash their appalling human rights record with the glamour of top-flight football,” said Sacha Deshmukh, the organization’s chief executive in Britain.

“Under Mohammed bin Salman, the human rights situation in Saudi Arabia remains dire — with government critics, women’s rights campaigners, Shia activists and human defenders still being harassed and jailed, often after blatantly unfair trials.”

In Newcastle, however, fans weary of Ashley’s ownership and the team’s middling performances during his tenure celebrated the sale outside the club’s stadium. Supporters of the club have for months taken to social media to champion the sale, and some even filed legal action against the Premier League to push the takeover forward.