A French court this week accepted Instagram posts as evidence to uphold a challenge to the will of French music star Johnny Hallyday, who died in 2017 at the age of 74.

The singer had excluded children Laura Smet (35) and David Hallyday (52) from his will, leaving his entire €100m (£89m) estate to his 44-year-old widow, Laeticia.

French law prohibits parents from disinheriting their children, but Hallyday’s will was drafted in English in California, where such behaviour is allowed.

However, Laura and David used their father’s Instagram posts to show the court that his true home was France and that, in accordance with French law, they were entitled to a share of his estate.

Their lawyers also compiled a chart tracking the singer’s movements from the social media site, the Daily Telegraph reports.

They showed that Hallyday had spent 151 days in France in 2015 and 168 in 2014 — enough, it was argued, for him to be considered a French resident.

The court accepted the digital footprints as proof and overturned the will, ruling that the inheritance dispute should be settled in France.

Pierre-Jean Douvier, a lawyer for Laura and David, said: “Laeticia Hallyday will get her share, but there are now five heirs: the singer’s widow, the two little girls they adopted, and Laura and David.”

However, Laeticia Hallyday’s lawyer, Ardavan Amir-Aslani, said he intends to appeal. He also revealed that France-born Laeticia had applied for US citizenship in March. This move could support her claim that the Hallydays’ main home was Los Angeles.

Amir-Aslani added: “Johnny and Laeticia obtained ‘green cards’ as permanent US residents five years ago. I am frankly astonished by the ruling of the court and it will not stand.”

The artist sold more than 100 million records during a career that spanned six decades.