The US supreme court justice Clarence Thomas took at least three additional trips funded by the billionaire benefactor Harlan Crow that the conservative justice failed to disclose, the chair of the Senate judiciary committee said on Thursday.

Crow, a Texas businessman and Republican donor, disclosed details about the justice’s travel between 2017 and 2021 in response to a judiciary committee vote last November to authorize subpoenas to Crow and another influential conservative, according to the committee chair, Senator Dick Durbin, a Democrat representing Illinois.

Related: Lindsey Graham vows to block Democrats’ supreme court ethics bill

“The Senate judiciary committee’s investigation into the supreme court’s ethical crisis is producing new information – like what we’ve revealed (Thursday) – and makes it crystal clear that the highest court needs an enforceable code of conduct, because its members continue to choose not to meet the moment,” Durbin said.

A supreme court spokesperson did not immediately respond to a request for comment, nor did a lawyer for Crow.

Thomas has previously come under criticism for failing to disclose gifts from Crow. Most recently, Thomas last week belatedly revised his 2019 financial disclosure form on to acknowledge that Crow had paid for his “food and lodging” at a hotel in Bali, Indonesia, and at a California club.

But the recent filing by Thomas failed to disclose that Crow had paid for his travel by private jet related to the Bali and California trips, and an eight-day excursion on a yacht in Indonesia, omissions that were revealed on Thursday in a redacted document that Durbin’s office said contained travel itineraries where Crow had provided the justice with transportation.

The document shows private jet travel in May 2017 between St Louis in Missouri, the state of Montana, and Dallas. It also shows private jet travel in March 2019 between Washington DC and Savannah, Georgia, and private jet travel in June 2021 between Washington DC and San Jose, California.

Under pressure from criticism over ethics, following a series of rows focusing mainly on Thomas and Samuel Alito, the most conservative justices, the nine justices of the supreme court last November adopted their first code of conduct.

However, critics and some congressional Democrats have said the code does not go far enough to promote transparency, continuing to leave decisions to recuse from cases to the justices themselves and providing no mechanism of enforcement.

Earlier this week, the South Carolina senator Lindsey Graham, the top-ranking Republican on the Senate judiciary committee, said he would block Democrats’ attempts to pass an ethics bill to rein in the US supreme court.

And Democratic congresswomen Alexandria Ocasio-Cortez said the court has been “captured and corrupted by money and extremism”, provoking a “crisis of legitimacy” that threatens the stability of US democracy.

Reuters contributed reporting