The Portuguese government agency responsible for granting citizenship is investigating Roman Abramovich's claims to Sephardi ancestry after he obtained EU citizenship last year.

The oligarch is believed to have taken advantage of a Portuguese law that gives naturalisation rights to descendants of Jews that were hounded out of both Spain and Portugal during the Inquisition of the late 1400s.

After securing his EU citizenship, Mr. Abramovich now faces an investigation by Portugal's Institute of Registries and Notary, the agency that confers citizenship and naturalisation rights.

In a statement to Reuters, the Justice ministry maintained that it was a routine procedure, saying: "It is a normal procedure adopted whenever there are situations or news that refer to any possible irregularity in the procedure carried out."

A spokesperson for the Chelsea owner said that they "welcome any review as it will only demonstrate the citizenship was obtained in accordance with the rules".

The Portuguese law was passed in 2015, and thousands of Sephardi Jews are believed to have made their applications for citizenship after a similar scheme in Spain ended in 2019. Potential applicants are vetted by genealogists to confirm their Sephardi history. 

Jewish genealogists in Porto are believed to have verified Mr. Abramovich's claims to Sephardi heritage, despite Sephardi Jews having very little presence in Russia.