Ancient Crimean gold treasures returned to Kyiv Monday after being stuck in a Dutch museum for nine years, where they were on show when Russia seized the Black Sea peninsula in 2014.

The Scythian artefacts -- some around 2,000 years old -- were on loan to Amsterdam's Allard Pierson museum when they were suddenly at the centre of a geopolitical crisis following Russia's 2014 annexation of Crimea.

Years of legal battles ensued, with both Kyiv and Moscow-controlled Crimean museums filing suits that the jewels should be in their hands, before the Dutch Supreme Court ruled this summer they should go to Ukraine.

"After almost 10 years of trials, artefacts from four museums of Crimea... returned to Ukraine," the National Museum of the History of Ukraine (NMHU) said on its website.

"They will be kept in the NMHU until the de-occupation of Crimea," it added.

Their return comes 21 months into Moscow's invasion, and is a symbolic victory for Kyiv, which has repeatedly vowed to retake Crimea.

Moscow has insisted that the hundreds of artefacts -- which include a golden helmet -- should be kept in Crimea, territory which it claims as its own.

"It belongs to Crimea, it should be there," Kremlin spokesman Dmitry Peskov said Monday in response to the jewels arriving in Ukraine.

The treasures were kept at the Allard Pierson museum throughout the legal battles, awaiting a ruling.

In June, the Netherlands' top court ruled they should be handed to Ukraine, and not to the four Crimean museums.

"This was a special case, in which cultural heritage became a victim of geopolitical developments," Allard Pierson director Els van der Plas said on the museum's website.

She said that, during the legal battles, the museum "focused on safely storing the artefacts until the time came to return them to their rightful owner."

"We are pleased that clarity has emerged and that they have now been returned," she added.