LISBON (REUTERS) - Portugal has blocked the sale of a 10 million euro (S$14.5 million) mansion belonging to sanctions-hit Russian billionaire Roman Abramovich, Publico newspaper said on Saturday (May 14), without citing its sources.

The property registry of the mansion in the luxury Quinta do Lago resort in the Algarve was frozen - meaning it cannot be changed - on March 25 at the request of the foreign ministry, a month after Russia's full invasion of Ukraine, Publico said.

The ministry did not immediately reply to a Reuters request for comment.

A spokesman for Abramovich did not respond to phone calls and messages seeking comment.

According to Publico, the former Chelsea soccer club owner tried to sell the property 15 days before Russia's invasion of Ukraine started through the Delaware-based Millhouse Views, owned by Millhouse, which manages his assets.

Portugal's largest bank, Caixa Geral de Depositos, noticed the move and alerted authorities, the newspaper said. The bank declined to comment.

Publico said the property is in plot 17 of Quinta do Lago's San Lorenzo North area. A Reuters witness said there was a signboard outside the gated mansion saying it had been sold.

Abramovich has been sanctioned by the British government and the European Union over his links to Russian President Vladimir Putin. He has denied having such ties.

The billionaire was granted Portuguese citizenship in April 2021 based on a law offering naturalisation to descendants of Sephardic Jews who were expelled from the Iberian peninsula during the Mediaeval Inquisition.

There is little known history of Sephardic Jews in Russia.

The case sent shockwaves across Portugal, leading public prosecutors to launch an investigation and to the detention of a rabbi responsible for the certification that allowed Abramovich to obtain citizenship.