Editor’s note: For readers who have not guessed, this story was our annual April Fools’ joke.
The blog was spotted by a Russian expatriate based in Seoul, who quoted extracts that he said pointed to it belonging to Yekaterina Putina, Putin's younger daughter.
The blog is written in Russian, Korean and German, wrote the expat, Vladimir Snegirov, on his LiveJournal account.
"When she is angry, she writes in German, when happy in Korean. She writes about her family only in Russian," he said.
The blog mainly describes the daily life of an expat abroad, but some entries, Snegirov wrote, clearly point to the writer being Putin's daughter.
"Why do I have to go to the embassy to speak to my own father?" she wrote on Feb. 12, adding, "And what's the point of a secure line when he doesn't tell me anything anyway?"
Putin has zealously guarded his family from media attention, and little is known about his two daughters, Yekaterina, 25, and Maria, 26.
A Korean newspaper reported in 2010 that Yekaterina had married the son of a Korean admiral and was now living in Seoul, although the Kremlin later denied the report.
No photos of Putin's daughters as adults have ever been published. One of the few photos that have surfaced shows the two daughters as teenagers but only from behind.
The writer of the blog, Seoulsister, which was deleted as of April 1, did not give her name. But an online cache of various posts suggested that she was in her mid-20s, Russian, recently married and sometimes had a tense relationship with her father.
"Sometimes I think I have disappeared, that I only exist as the girl with her head turned round," she wrote earlier this year. "I remember how we used to brush our hair forward, put on sunglasses and bump around the house. He didn't like that, did he?"
She follows the entry by posting a YouTube video of Madonna singing "Papa Don't Preach." It's a video she has posted five times in the last six months.
There is little mention of politics in the blog, but some opposition activists, perhaps a bit too eagerly, are taking to an entry on Dec. 24 where she says, "I think I may wear white today," as showing her backing of a mass rally that took place on Prospekt Akademika Sakharova, where people wore white ribbons.
A number of experts dismissed the possibility that the blog might have been linked to Putin but said the absence of information about Putin's family was the problem and that there would be more such speculation in the future.
"People are jumping on the smallest piece of information and then blowing it up," said Sergei Markov, a former State Duma deputy with United Russia.
The Kremlin refused to answer questions about the blog, saying it did not comment on Putin's family.
The last entry in the blog was dated March 4, the day of the presidential election that saw Putin claim victory and later shed tears at a rally. The blogger writes, "He cried at my wedding too. Or was that the wind?"