Google was ordered by a US judge to turn over the content of emails of the son of Farkhad Akhmedov to the Russian oligarch’s former wife in her pursuit of a £450mil divorce judgment.

The skirmish over the email accounts is part of one of London’s largest divorce fights - involving a super yacht in Dubai and litigation funder Burford Capital Ltd - which landed before a judge in San Jose, California, in the federal court closest to Google’s Mountain View headquarters 14 miles away.

Tatiana Akhmedova alleges that her former husband transferred assets to their son Temur to avoid paying a London court’s judgment that she says remains “almost entirely unsatisfied”.

In a dispute that tugs at the boundaries of US privacy law, Magistrate Judge Virginia M. DeMarchi said she was inclined to comply with the London court’s ruling allowing Akhmedova to seek her son’s emails from Google. The judge - who announced her decision during a hearing Tuesday and promised a written order later - said the information released should not go beyond the requirements of the litigation in London.

The information from the emails will be used to learn whether Temur assisted his father in the fraudulent transfer of assets, and if so, to win a judgment against him, Tatiana Akhmedova said in a filing.

DeMarchi’s ruling follows a search of Temur’s apartment by his mother’s legal team that was authorised by a London judge who has accused the son, a financier, of destroying evidence, according to a report in the Times of London.

Google argued that it is forbidden under US law from disclosing contents of a communication without an account user’s “express consent”. That first requires Temur Akhmedov to log into his accounts so Google can verify they belong to him, Julie E. Schwartz, a lawyer for Google, told DeMarchi at the hearing.

“It’s very important for Google to have verification based on access,” Schwartz said. She also said Google faces legal liability for improperly disclosing the information. “This has broader implications than just this case here today,” she added.

Akhmedova said her son made a sworn statement in the British court confirming he’s the user of the Google accounts. Temur Akhmedov has claimed he doesn’t have valid passwords for his accounts and is unable to locate the mobile devices associated with them. But Google expressed concern in a filing about taking his word for it in light of his alleged “deceptive and destructive behaviour” in the British case.

The company said it suggested Temur could regain access by buying new SIM cards for his devices. But he would still have to sign in and Google would require his verified consent to release the information.

James H. Power, a lawyer for Akhmedova, said he understood Google’s desire to limit its legal exposure. Nevertheless, Power told the judge, “we stand firm that we did everything we can to access this in accordance with the law, and considering the interest of Google as well.”

“The only person saying they’re not his accounts is Google, without any evidence that they’re not his accounts,” Power said.

Nicholas Koulermos, a representative of Temur Akhmedov, didn’t immediately respond late Tuesday to phone and email messages seeking comment. Google didn’t respond to a request for comment about the ruling.

 - Bloomberg