The Democratic-led impeachment investigation in Donald Trump was delayed for about four hours after a group of Republicans stormed the closed-door test session with a Defense Department official.
Lawmakers said the measure compromised national security because some Republicans brought electronic devices into a safe room.
The interview with Laura Cooper, a senior official who oversees Ukraine's policy, resumed after verifications by Capitol security officials.
Laura Cooper's evidence was delayed by about four hours
Democrat Debbie Wasserman Schultz said she had just entered the room when Republican lawmakers passed the Capitol police.
"Literally, some of them were just shouting about the president and what we are doing to him, and that we have nothing and just everything that supports the president," she said.
A number of diplomats were interviewed in the impeachment investigation into what is called the Sensitive Compartment Information Center (SCIF).
It is a safe room where members can listen to information classified with a strict ban on electronic devices.
Democrat Bennie Thompson, who chairs the House's Homeland Security Committee, said Republicans "intentionally brought their electronic devices" into the safe area.
The "unprecedented security breach raises serious concerns" for committee chairmen who maintain safe facilities at the Capitol, Thompson wrote in a letter to the House of Arms sergeant calling for action to be taken against members of Congress involved in the breach.
Senator Lindsey Graham criticized his fellow Republicans for the tactic, calling them "crazy" to "run away from SCIF."
However, the Republicans who participated in the protest were thoughtless when Steve Scalise accused the Democrats of running a "Soviet-style process" that "should not be allowed in the United States."
"We will not be intimidated," he said.
After the statement was resumed, Cooper explained the process of distributing military aid and was asked if appropriate measures were followed in Ukraine, according to a person familiar with the interview.
This comes just a day after a US diplomat told lawmakers that he was informed that President Trump was withholding Ukraine's military aid unless the country's president pledged to investigate political rival Joe Biden and his son Hunter. .
:: Sky News is broadcasting a channel without Brexit on weekdays from 5 pm to 10 pm on Sky 523