Mitt Romney says he thinks there’s a “bombshell” in Donald Trump’s tax returns.
Trump has said his accountants are working on his returns and that he’ll release them eventually.
Romney is also calling on Marco Rubio and Ted Cruz to release their tax returns.
The former Massachusetts governor came under intense scrutiny in 2012 over his own tax filings.
Romney also says he believes Trump has the clearest path to the Republican nomination and that there is “a slimmer and slimmer opening” for his rivals unless the field narrows.