(Reuters) -A Ukrainian lawmaker who was formally notified this week that he was suspected of treason for allegedly cooperating with Russia's military intelligence said on Wednesday a Kyiv court had ordered him detained for 60 days.

Oleksandr Dubinsky, who is on a U.S. sanctions list, was told on Monday he was also suspected of spreading misinformation about Ukraine's political leadership, officials said.

"The court supported the prosecution's request to impose a remand on me in the form of detention for 60 days until January 12, 2024," Dubinsky said in a video posted on his Telegram channel. Dubinsky did not detail the reason for his detention.

Reuters could not independently verify the video, which showed Dubinsky in a building with a man in a Ukraine security service uniform behind him.

Ukraine's security service, the SBU, on Monday said on Telegram that a politician was under suspicion of treason, but did not name the suspect.

Lawmaker Yaroslav Yurchyshyn, first deputy head of the parliamentary committee on anti-corruption policy and lawmaker Oleksiy Honcharenko both named Dubinsky as the subject of the action.

"Dubinsky received a (notice of) suspicion of state treason. He was searched today," Honcharenko said on Telegram.

Dubinsky called the notice of suspicion fabricated and "based on the absolute lies of top state officials".

The lawmaker was expelled from the ruling Servant of the People party in 2021 after he was put on a U.S. sanctions list over alleged election meddling. He denied those accusations and continued to work in parliament.

The SBU said the suspect was a member of a criminal organisation, financed by Russia's military intelligence.

The criminal organisation was created in 2016 and included as well an ex-lawmaker, their aide, and an ex-prosecutor, it said.

"It is established that on the instructions of the Russian special services, it organized events to discredit the image of Ukraine in the international arena in order to worsen diplomatic relations with the United States and complicate Ukraine's accession to the European Union and NATO," the State Investigative Bureau said in a separate statement published on its website.

In January 2021, The United States imposed sanctions on several Ukrainian individuals and entities, including Dubinsky, accusing them of U.S. election interference and associating with a pro-Russian Ukrainian lawmaker linked to efforts by then President Trump's allies to dig up dirt on now-President Joe Biden and his son.

(Reporting by Yuliia Dysa and Lidia Kelly; Editing by Sharon Singleton and Lincoln Feast.)