HOUSE SPEAKER Robert DeLeo said Tuesday that the allegations against Rep. David Nangle, a member of his Democratic leadership team, are “serious and troubling and, if true, represent a significant betrayal of the public trust.”

But DeLeo did not say what, if any, steps the House would take regarding Nangle.

Nangle was arrested by federal authorities on Tuesday for an allegedly years-long spree of spending his campaign funds for personal use and lying on campaign finance disclosures, applications for bank loans, and federal tax returns. The US Attorney’s office said Nangle had large gambling debts and used his political campaign account to cover personal expenses.

Internal House rules prohibit members from soliciting or accepting “any compensation or political contribution other than that provided for by law for the performance of official legislative duties.”

The internal House Ethics Committee, made up of legislators, can initiate an investigation into a violation of House rules on the basis of a request from the House speaker; a sworn complaint by a House member, officer or employee; or a majority vote of members of the Ethics Committee.

Ethics Committee Chairman Rep. Chris Markey, a Dartmouth Democrat, said he only found out about the charges against Nangle late Tuesday morning from the news media. Markey declined to comment on whether the Ethics Committee will investigate Nangle, saying any investigation is confidential, and it would be a violation of the rules for him to speak about it.

A written statement provided by DeLeo Tuesday afternoon did not say whether DeLeo would refer the matter to the Ethics Committee; consider stripping Nangle of his leadership position as second division chair, which comes with an additional stipend; or revoke his membership on committees relating to ethics and rules.

DeLeo, in the statement, said he “was shocked and disappointed” when he learned of the indictment on Tuesday.

“Representative Nangle has been a friend and colleague for over 20 years. Never once during that time did I have an inkling that he had a gambling problem, much less a gambling problem as extensive as what has been reported today,” DeLeo said.

DeLeo said the House of Representatives had received a subpoena in the investigation, which it complied with. “The House of Representatives cooperated fully with this subpoena and will continue to cooperate fully with the United States Attorney’s investigation,” he said.

DeLeo said he has been asked by the US Attorney’s Office not to talk about the investigation, so he will not be commenting further.

If the House Ethics Committee does investigate Nangle, the investigation would only become public when it is completed, if the committee deems a violation to have merit, then files a report with the House Clerk. The committee can recommend discipline, ranging from a public reprimand to expulsion, and it would be up to members of the House whether to adopt that recommendation.

Because Nangle is a member of the Ethics Committee, the committee could be put in the awkward position of investigating its own member. Under House rules, Nangle would not be part of that investigation.

Leaving the federal courthouse after his arraignment on Tuesday, Nangle did not answer questions shouted by reporters about whether he plans to resign.

The last time a House member was expelled was in 2014 when Rep. Carlos Henriquez, a Boston Democrat, was convicted and was serving time in jail for assaulting a woman who refused to have sex with him.

Sen. Brian Joyce, a Milton Democrat indicted on federal corruption charges in 2017, announced he would not run for reelection before the Senate took any action. But he was stripped of his leadership title and committee assignments even before he was arrested, after a series of news stories.

State Republicans are already using Nangle’s arrest to criticize the Democratic stronghold on Beacon Hill.

Massachusetts Republican Party Chairman Jim Lyons said Nangle’s arrest is a symptom of “one-party rule” in Massachusetts. “Having a Democrat-dominated state Legislature has been a stain on accountability,” Lyons said. “There has to be a balance in the state Legislature, and if not, you can bet this serial pattern of abuse and misconduct will keep happening again and again.”

Lyons pointed to the criminal convictions of three successive Democratic House speakers – Charles Flaherty, Tom Finneran, and Sal DiMasi – and the federal charges leveled against Joyce, who died before his case went to trial.