MOSCOW — A team led by the Russian opposition leader Aleksei A. Navalny published a sprawling investigation on Tuesday describing a secret palace built for President Vladimir V. Putin on the Black Sea, with the report’s release coming less than 24 hours after Mr. Navalny had been ordered jailed
The report was the latest swipe in Mr. Navalny’s dramatic battle with Mr. Putin that is playing out before an online audience of millions, and it arrived as the opposition leader’s supporters seek to energize street protests planned for this weekend.
The investigation — complete with floor plans, financial details and interior photographs of a compound Mr. Navalny says cost more than $1 billion — appeared to offer the most comprehensive accounting yet of a huge residence the president is said to have built for himself on southern Russia’s verdant seashore.
The Kremlin denied the findings in the report, which went online Tuesday as a 113-minute YouTube video and a lengthy, illustrated text version that also invited users to post pictures of Mr. Putin’s purported luxury to Facebook and Instagram. The video has been viewed more than four million times on YouTube.
“They will keep on stealing more and more, until they bankrupt the entire country,” Mr. Navalny says in the video, referring to Mr. Putin and his circle. “Russia sells huge amounts of oil, gas, metals, fertilizer and timber — but people’s incomes keep falling and falling, because Putin has his palace.”
Mr. Navalny — who flew home Sunday after being treated in Germany for a near-fatal poisoning in Siberia in August — was arrested at passport control in full view of Russians watching live broadcasts of his arrival. On Monday, Mr. Navalny was ordered jailed for 30 days during a proceeding in a makeshift courtroom at a Moscow-area police station, a portrait of a Stalin-era secret police chief on the wall behind him.
Before being led away, Mr. Navalny called on Russians to “take to the streets” against Mr. Putin in videos his staff posted online. And on Tuesday, his staff posted the palace investigation, which Mr. Navalny recorded while he was in Germany. Text in the video’s opening frames exhorts viewers to join demonstrations at 2 p.m. on Saturday in “the central streets of your cities.”
“Navalny has been fighting for our rights for many years,” the text says. “It is now our turn to fight for him.”
Reports of a palace being built for Mr. Putin near the Black Sea resort town of Gelendzhik first emerged more than a decade ago. Satellite images show an imposing, rectangular building, a grand alley, a helipad and other structures connected by a winding road on a remote section of hilly coastline.
The project has long been cloaked in secrecy, and Mr. Putin’s spokesman on Tuesday repeated his denials that Mr. Putin had a palace there. His official Black Sea residence is a more humble compound in the city of Sochi, a 150-mile drive away.
“We already explained years ago that Putin has no palace in Gelendzhik,” the spokesman, Dmitri S. Peskov, was quoted as saying by Russian media.
Mr. Navalny presented financial records and other evidence that he said points to the palace having been built for Mr. Putin by associates and called it “the biggest bribe in history.”
Some details had previously appeared in Russian news reports, but Mr. Navalny presented them in his trademark, populist style. His past investigative reports of the Russian elite’s wealth had propelled him to prominence as an anti-corruption activist and opposition leader.
His team found that nearly 30 square miles of land around the palace was controlled by Russia’s domestic intelligence agency, that the airspace above it was restricted and that the coast guard did not allow boats within one mile.
There were also new, eye-popping depictions of what the report said was Mr. Putin’s lavish lifestyle.
A contractor, Mr. Navalny said, had leaked detailed floor plans, and his team used them to create interactive, three-dimensional models of the interior. The ground floor includes a spa, a movie theater, a wine cellar and an outdoor area with fountains described as an “aqua disco.” The next floor up, according to the report, has a larger theater, a casino hall and a windowless hookah lounge with a pole-dancing stage.
The report also describes an underground hockey rink, a church, a tunnel to the seaside and a 260-foot-long bridge leading to a teahouse.
“We are publishing the blueprints of his palace,” Maria Pevchikh, who heads Mr. Navalny’s investigative unit, wrote on Twitter, referring to Mr. Putin. “Alas, the grandpa crazy about his own security won’t be able to use it anymore.”
In remarks made to journalists before the report’s release, Mr. Peskov, the Kremlin spokesman, brushed aside Western calls for Mr. Navalny to be freed.
“We hear these calls, but in this case we cannot and will not take these statements into consideration,” Mr. Peskov said. “This is an absolutely domestic issue, and we will not allow anyone to interfere in it.”
Mr. Navalny himself spent Monday in a high-security section of a notorious Moscow jail, Matrosskaya Tishina. In a message to his supporters that he passed along to his lawyers and that was posted on Instagram, Mr. Navalny said he had no regrets about returning to Russia, despite having been arrested.
Of the special jail in which he was being held, Mr. Navalny wrote: “I read about it in books, and now here I am myself. That’s Russian life for you.”