The former British spy who authored a controversial dossier on behalf of Donald Trump’s political opponents alleging ties between Trump and Russia reached an agreement with the FBI a few weeks before the election for the bureau to pay him to continue his work, according to several people familiar with the arrangement.

The agreement to compensate former MI6 agent Christopher Steele came as US intelligence agencies reached a consensus that the Russians had interfered in the presidential election by orchestrating hacks of Democratic Party e-mail accounts.

Although Trump has derided the dossier as ‘‘fake news’’ compiled by his political opponents, the FBI’s arrangement with Steele shows that the bureau considered him credible and found his information, while unproved, to be worthy of further investigation.

Ultimately, the FBI did not pay Steele. Communications between the bureau and the former spy were interrupted as Steele’s dossier became the subject of news stories, congressional inquiries, and presidential denials, according to the people familiar with the arrangement, who spoke on the condition of anonymity because they were not authorized to discuss the matter.

At the time of the October agreement, FBI officials probing Russian activities, including possible contacts between Trump associates and Russian entities, were aware of the information that Steele had been gathering while working for a Washington research firm hired by supporters of Democratic presidential nominee Hillary Clinton, according to the people familiar with the agreement. The firm was due to stop paying Steele as Election Day approached, but Steele felt his work was not done, these people said.

Steele was familiar to the FBI, in part because the bureau had previously hired him to help a US inquiry into alleged corruption in the world soccer organization FIFA. The FBI sometimes pays informants, sources, and outside investigators to assist in its work. Steele was known for the quality of his past work and for the knowledge he had developed over nearly 20 years working on Russia-related issues for British intelligence. The Washington Post was not able to determine how much the FBI intended to pay Steele had their relationship remained intact.

The dossier he produced last year alleged, among other things, that associates of Trump colluded with the Kremlin on cyberattacks on Democrats and that the Russians held compromising material about the Republican nominee.

These and other explosive claims have not been verified, and they have been vigorously denied by Trump and his allies.

The FBI, as well as the Senate Intelligence Committee, is investigating Russian interference in the election and alleged contacts between Trump’s associates and the Kremlin.

On Tuesday, House Speaker Paul Ryan, a Wisconsin Republican, told reporters that he had seen ‘‘no evidence so far’’ of Trump campaign contacts with Russia but said a bipartisan House inquiry would proceed so that ‘‘no stone is unturned.’’

The revelation that the FBI agreed to pay Steele at the same time he was being paid by Clinton supporters to dig into Trump’s background could further strain relations between the law enforcement agency and the White House.

A spokesman for the FBI declined to comment. Steele’s London-based attorney did not respond to questions about the agreement.

White House press secretary Sean Spicer declined to comment.

Steele, 53, began his Trump investigation in June 2016 after working for another client preparing a report on Russian efforts to interfere with politics in Europe.

US intelligence had been independently tracking Russian efforts to influence electoral outcomes in Europe.

Steele was hired to work for a Washington research firm, Fusion GPS, that was providing information to a Democratic client. Fusion GPS began doing Trump research in early 2016, before it hired Steele, on behalf of a Republican opposed to the businessman’s candidacy. The firm declined to identify its clients.

Steele’s early reports alleged a plan directed by President Vladimir Putin of Russia to help Trump in 2016.