BANGKOK — Malaysia‘s attorney general said on Tuesday that he had closed an investigation into transfers of hundreds of millions of dollars into Prime Minister Najib Razak’s personal bank accounts because no laws had been broken.
The decision, greeted with outrage and cynicism by the opposition, appears to prolong the embattled premiership of Mr. Najib, who has struggled to explain why nearly $700 million had been transferred to him.
Attorney General Mohamed Apandi Ali told reporters at a hastily convened news conference on Tuesday in the country’s administrative capital, Putrajaya, that he had ordered the anticorruption commission to close the investigation into the money that Mr. Najib received.
Mr. Apandi, who was appointed by the prime minister last year after the previous attorney general abruptly left office, said the largest amount, $681 million, “was a personal donation” from the Saudi royal family.
“I am satisfied that there was no evidence to show that the donation was a form of gratification given corruptly,” Mr. Apandi said in a statement released by his office.
The statement also said that part of the money — $620 million — was returned to the Saudi royal family in 2013 “because the sum was not utilized.”
In a statement of his own on Tuesday, Mr. Najib said that he welcomed the attorney general’s findings, and that the matter “has been comprehensively put to rest.”
The attorney general’s remarks were the most explicit on the transfers to date.
But no reason was provided as to why the Saudis would send Mr. Najib such a large sum.
Nor did the attorney general say how much of the $61 million that Mr. Najib did not send back was spent.
One of the more outspoken members of the opposition, Rafizi Ramli, sarcastically called Mr. Najib “the luckiest person” to have received so much money, and “most generous” for having returned so much of it.
“This can only happen in fairy tales,” Mr. Rafizi was quoted as saying by Malaysiakini, a news website. He called the prime minister a clown and said the explanation given on Tuesday by the attorney general made the situation “more ridiculous.”
In addition to the assertion that Mr. Najib had received money from the Saudis, the attorney general’s statement suggested that the prime minister was unaware that millions of dollars had been transferred into his personal accounts from a company owned by the Finance Ministry known as SRC.
Documents from the investigation show that those transfers amounted to about $10 million. The attorney general’s office said there was “no evidence” that Mr. Najib “had any knowledge” of these transfers.
Mr. Najib “was of the belief” that any of the money he spent had come from the Saudi royal family, the statement said.
The case of SRC is potentially explosive because it involves the savings of Malaysian government employees: SRC received a loan of more than $930 million from the government fund that manages the retirement savings of civil servants, a decision approved by Mr. Najib’s cabinet.
Mr. Najib’s government has moved aggressively to shut down leaks that led to the investigation. Last year, the police raided the offices of the anticorruption commission, the license of a crusading news organization was suspended and Mr. Najib purged his deputy prime minister, who had been pressing for further investigations.
At the center of Mr. Najib’s troubles is a sovereign wealth fund called 1Malaysia Development Berhad, or 1MDB, which has the prime minister as chairman of its board of advisers.
The opposition is leading calls for further investigations into the fund’s billions of dollars in debts, its struggles to repay them, and opaque transactions involving offshore tax havens.
The lavish spending of Mr. Najib’s wife and his stepson’s real estate holdings in the United States have also come under scrutiny.
In September, people with knowledge of the investigation said that a United States federal grand jury was examining allegations of corruption involving Mr. Najib and people close to him,
The inquiry, being run by a unit of the Justice Department that investigates international corruption, was said to be focused on properties in the United States purchased in recent years by shell companies belonging to his stepson, as well as other real estate connected to a close family friend.
Mr. Najib has prevailed despite large street protests in August against him, as well as a spirited campaign to unseat him by Mahathir Mohamad, a former prime minister and senior member of Mr. Najib’s party.
An earlier version of this article misstated the role of Prime Minister Najib Razak in the 1Malaysia Development Berhad sovereign wealth fund. He is chairman of the board of advisers, not chairman of the fund.