According to reports emerging from Russia, Alexander Petrov was shot at his home near Vyborg in the western part of the country.
The tragedy meant that Vitaly, who was having his first appearance as a drivers' steward, was unable to continue in his role and has immediately returned home to Russia.
A statement issued by motor racing's governing body on Saturday night said: "The FIA confirms that, due to a personal bereavement, the Driver Steward for the 2020 FIA Formula 1 Portuguese Grand Prix, Vitaly Petrov, will not continue with his duties for the remainder of the weekend.
"The thoughts of the FIA are with Vitaly and his family at this time."
The FIA has announced that Bruno Correia, the safety car driver in Formula E and WTCR, will take over Petrov's role on the stewards' panel on race day in Portugal.
Formula 1 race director Michael Masi said: "Firstly, and most importantly, our thoughts with Vitaly and his family at this time. From that perspective with regards to a replacement driver steward we're fortunate in that long-term FIA safety car driver in Formula E and for the World Touring Car Cup Bruno Correia lives locally in Portimao. So he will join us tomorrow morning.
"We arranged everything with regards to COVID testing and so forth, and he will join the stewards' panel in the morning. Obviously we're very thankful to Bruno, and as I said our thoughts are with Vitaly and his family."
Petrov is a former grand prix driver who was the first Russian to compete in Formula 1. He took part in 57 grands prix between 2010 and 2012 for the Renault and Caterham teams.
His best result was when he finished third for Renault at the 2011 Australian GP, behind race winner Sebastian Vettel and Lewis Hamilton.
Petrov is perhaps most famously remembered, however, for his defensive driving at the 2010 Abu Dhabi Grand Prix when he held off Fernando Alonso in the title-deciding season finale.
His drive that evening meant Alonso failed to score the points he needed to secure the world title, meaning Sebastian Vettel grabbed his first championship crown.
After leaving F1, Petrov raced in the DTM for Mercedes in 2014, prior to switching to sportscars. He has regularly driven for the SMP team since and last year finished third at Le Mans.
Petrov's appearance on the stewards' panel in Portugal this weekend caused some controversy, however, following recent remarks that the Russian made about F1's anti-racism stance.
However, the FIA defended its decision to select Petrov by stating that personal views were not taken into consideration when choosing who can act as an official.