The US supreme court justice Clarence Thomas said on Friday he was advised the “personal hospitality” extended to him for more than 25 years by the Republican mega-donor Harlan Crow, detailed in an explosive report by ProPublica, did not have to be reported under ethics rules. “I have endeavoured to follow that counsel throughout my tenure,” Thomas said in a rare statement, “and have always sought to comply with the disclosure guidelines.” The statement did little to dampen controversy surrounding the 74-year-old conservative or lessen fire from the political left. Thomas is the longest-serving current justice, nominated by George HW Bush in 1991. On Thursday, ProPublica reported that he has long accepted trips from Crow including travel on private jets and yachts and stays at exclusive resorts. Justin Elliott, one of the report authors, said: “This is the text of the law ethics lawyers told us he violated. Gifts – such as private jet travel – need to be reported, unless they are ‘food, lodging, or entertainment received as personal hospitality’. This is in the statute itself and predates the recent filing guidance update.” That update went into effect on 14 March. In a subsequent letter to Sheldon Whitehouse, a Democratic senator from Rhode Island, Roslynn Mauskopf, director of the Administrative Office of the United States Courts, said gifts not covered by the reporting exemption included gifts “such as transportation that substitutes for commercial transportation”. Thomas said: “Early in my tenure at the court, I sought guidance from my colleagues and others in the judiciary, and was advised that this sort of personal hospitality from close personal friends, who did not have business before the court, was not reportable.” He added: “It is, of course, my intent to follow this guidance in the future.” Supreme court justices, however, largely sit above federal ethics regulations, essentially governing themselves. Thomas also said Harlan and Kathy Crow were among his “dearest friends” and had joined him and his own wife, the rightwing activist Ginni Thomas, “on a number of family trips”. In 2004, 13 years into Thomas’s time on the court, the Los Angeles Times reported gifts from Crow including a Bible once owned by Frederick Douglass. After that, in the same paper’s words this week, Thomas “stopped disclosing” gifts. The Washington Post noted that Thomas has disclosed just two gifts since 2004. ProPublica noted that Crow’s generosity to Thomas was reported in 2011, by the New York Times and Politico. The latter, it said, “revealed that Crow had given half a million dollars to a Tea Party group founded by Ginni Thomas, which also paid her a $120,000 salary”. ProPublica reported the existence of a painting hung at Crow’s resort in New York state and showing Thomas smoking a cigar in company including Leonard Leo, head of the Federalist Society, which played a major role in tilting the supreme court right with three confirmations under Donald Trump. Crow said he and his wife had been friends with the Thomases since 1996, giving gifts “no different from the hospitality we have extended to our many other dear friends”. He also claimed: “We have never asked about a pending or lower court case, and Justice Thomas has never discussed one, and we have never sought to influence Justice Thomas on any legal or political issue. More generally, I am unaware of any of our friends ever lobbying or seeking to influence Justice Thomas on any case, and I would never invite anyone who I believe had any intention of doing that.” Accountable.US, an advocacy group, contended Thomas was wrong to say Crow did not have business before the court. It said: “For three decades, Crow has served on the board of trustees of the American Enterprise Institute (AEI), which has published and taken credit for multiple amicus briefs filed with the supreme court by the group’s president and scholars.” Crow joined the AEI in 1996, the same year he said he became friends with Thomas. Kyle Herrig, president of Accountable.US, said: “First Justice Thomas hid decades of lavish gifts and travel funded by Harlan Crow, but now he’s outright lying when he says this major conservative donor had no interest in the work of the supreme court. “The truth is clear: this is an unprecedented story of corruption at the highest levels, and those involved must be held accountable.” Thomas is the senior conservative of six on the nine-member court, his influence growing through a series of controversial conservative rulings, not least the removal of the right to abortion in Dobbs v Jackson last year. In a concurring opinion in Dobbs, Thomas suggested similar rights – same-sex marriage, gay sex and contraception access – should be reviewed. He did not mention interracial marriage. Thomas is Black. His wife is white. The ProPublica report prompted Senate Democrats to call for an investigation – and some on the left to renew calls for impeachment. Dick Durbin, a Democratic senator from Illinois, said: “Supreme court justices must be held to an enforceable code of conduct, just like every other federal judge … the Senate judiciary committee will act.” Alexandria Ocasio-Cortez, the progressive congresswoman from New York, said “Thomas must be impeached”, as the court was becoming known for “rank corruption, erosion of democracy and the stripping of human rights”. Impeachment is highly unlikely, even given other calls regarding Ginni Thomas’s efforts in support of Trump’s attempt to overturn the 2020 election and Clarence Thomas’s failure to recuse himself from a related case. Like Crow, Ginni Thomas has claimed not to talk to her husband about cases or politics. Writing for Slate on the ProPublica report, Dahlia Lithwick and Mark Joseph Stern said: “Clarence Thomas broke the law, and it isn’t particularly close. “Thomas broke … a law which contains serious civil penalties, though the bogus technicality on which he relies, in addition to his political clout, will be more than enough to ensure that he never faces any actual legal consequences.”