US Senator Elizabeth Warren has sent a private letter to Barclays chair Nigel Higgins, questioning the bank's handling of former CEO Jes Staley's relationship with the late sex offender Jeffrey Epstein.

Warren claimed Barclays showed an 'apparent failure to meaningfully investigate' ties between Staley and Epstein. She said it was 'deeply unclear how Barclays failed to uncover this decades-long relationship.'

Staley is scheduled to be questioned by the US House Committee on Oversight and Reform on Thursday in a closed-door interview. The committee is investigating Epstein's network.

According to House Oversight Chair James Comer, Staley defended Epstein and encouraged JPMorgan Chase to retain him despite internal red flags. Staley spent more than three decades at JPMorgan before joining Barclays in 2015, according to reports.

Epstein died in prison in August 2019 while awaiting trial on child sex-trafficking charges.