Russian investigators are carrying out a probe into art valuations by experts at one of the country's top museums, Moscow's Tretyakov Gallery, a gallery spokeswoman said Wednesday.
"The investigation is continuing outside the gallery's premises," spokeswoman Anna Kotlyar told AFP.
She confirmed that investigators had carried out searches in the gallery on Tuesday, but said she had "minimal information" and could not comment further.
In one of the most high-profile scandals to hit Russia's art world in recent years, the powerful Investigative Committee has launched a probe into paintings allegedly smuggled out of the country after experts from the Tretyakov Gallery assessed them at a fraction of their true price.
In a statement, investigators said they had arrested a 33-year-old local government official at Moscow's Vnukovo airport as he tried to take five paintings out of the country, declaring their total value as less than 180,000 rubles (US $3,606).
The suspect gave "false information about the value of the paintings, which is really no less than 1.9 million rubles ($38,000)," investigators said.
He is under investigation for possible smuggling of cultural artifacts, which carries a maximum jail sentence of seven years.
The paintings apparently included a signed work by a well-known 20th century painter, Pyotr Konchalovsky, the RIA Novosti news agency reported.
Investigators said they were carrying out searches in the expert department of the Tretyakov Gallery.
Experts at top art museums in Russia have a lucrative sideline in giving such valuations and some have been accused of legitimising faked paintings as works by Russian masters, which then sell for top prices to collectors from the former Soviet Union.
The Tretyakov Gallery, a must-visit for most visitors to Moscow, specialises in Russian art and contains masterpieces including Kazimir Malevich's "Black Square" and paintings by Wassily Kandinsky and Marc Chagall.
The director of the Tretyakov Gallery, Irina Lebedeva, was sacked after six years in February in a surprise decision, with the culture ministry accusing her of failing to raise visitor numbers. She was replaced by Zelfira Tregulova, a former organiser of international exhibitions of Russian art.