US senator Elizabeth Warren has asked JPMorgan’s chief executive, Jamie Dimon, to explain any contact he or the bank may have had with Jeffrey Epstein, after newly released documents appeared to link Epstein to lobbying over a UK tax on bankers’ bonuses. The issue matters because it revives scrutiny of one of the world’s most powerful bankers and raises wider questions about how closely JPMorgan and senior executives were connected to Epstein despite his criminal history.

Warren’s letter, published by the Senate banking committee, cited a 2009 email in which Epstein appeared to suggest Dimon should lobby the then chancellor, Alistair Darling, and Peter Mandelson allegedly replied that Dimon should “mildly threaten” him. JPMorgan says Dimon never met Epstein, was not involved in decisions about Epstein’s account, and that the bank ended the relationship in 2013; it also rejected claims from former executive Jes Staley that he discussed Epstein with Dimon. Warren said the emails and related reporting raise serious questions about the extent of the relationship, while the bank said it regretted the association and would not have kept Epstein as a client had it known of ongoing crimes.