HONOLULU — The Hawaii state employee who mistakenly sent an alert warning of a ballistic missile attack earlier this month is refusing to cooperate with federal and state investigators, officials said Thursday.

The head of the Federal Communications Commission Public Safety and Homeland Security Bureau told a US Senate hearing the FCC was pleased with the cooperation it’s received so far from Hawaii Emergency Management Agency leadership.

But Lisa Fowlkes said the commission was disappointed that the agency employee who transmitted the false alert was refusing to cooperate.

“We hope that person will reconsider,” she told Senate commerce committee members.

Hawaii Emergency Management Agency spokesman Richard Rapoza said his agency has encouraged all employees to cooperate with all investigations. But he said this employee also has refused to cooperate with the agency’s internal investigations.

Rapoza said he couldn’t speak to why the employee wasn’t cooperating with federal investigators.

“With regard to our internal investigations, he has taken the position that he provided a written statement shortly after the incident, and doesn’t need to speak to investigators because he has nothing to add,” Rapoza said in an email.

The agency has not identified the employee. He continues to work at the agency though has been reassigned to a section where he doesn’t have access to the warning system.

An FCC spokeswoman didn’t immediately respond to a question about what reason the employee has given for not cooperating with its probe.

The alert sent to cellphones, TV and radio stations in Hawaii on Jan. 13 caused widespread panic and confusion. The problem was compounded by the lengthy amount of time — 38 minutes — it took the emergency management agency to send a corrected alert.

Sen. Brian Schatz told the committee he was introducing legislation that would make it clear that the authority to issue missile alerts rests with the U.S. departments of defense and homeland security, not with state and local governments.

“It is increasingly clear to me that if we get all 50 states and all the territories and 3,007 counties across the country participating in this program, the likelihood of another mistaken missile alert as a result of human or bureaucratic error is not zero,” Schatz said.