Washington(CNN) Democratic Rep. Nydia Velázquez called Wednesday for a commission to investigate Hurricane Maria death tolls, after a report published last week in a prestigious medical journal revealed an estimated 4,645 people died as a result of the disaster last year.

"We need an analysis of how this low death count may have shaped the inadequate federal response," she said during a news conference with her fellow Congressional Hispanic Caucus members. "Today, I am calling for the establishment of an independent commission similar to what we had after 9/11, to examine the death toll, the federal response and how FEMA and other agencies may have responded sluggishly based on artificially low numbers."

The official death toll in Puerto Rico has been the subject of substantial controversy since Hurricane Maria hit the island, a US territory, on September 20. CNN and other news outlets have used government statistics and extensive interviews with families of the deceased and funeral home directors to question the Puerto Rican government's official tally of deaths.

The figure published in the Harvard study dwarfs Puerto Rico's official death toll of 64, which the article's authors called a "substantial underestimate" of Hurricane Maria's death toll.

Still, the exact death toll is likely to remain a mystery. Experts previously have told CNN it is difficult to say with certainty whether a hurricane "caused" some of the deaths, especially those that occurred because of the chaotic and unsafe conditions that have lingered for months in Puerto Rico.

Velázquez, who is originally from Puerto Rico but represents New York in the House, also said she plans to introduce legislation to investigate the deaths on the island, but didn't elaborate.

She blames the Trump administration's response to Hurricane Maria as the reason for the number of deaths revealed in the study, which is more than double the deaths as a result of Hurricane Katrina in 2005.

"I guess in (President Donald Trump's) mind, fellow citizens in Puerto Rico and the Virgin Islands are not entitled to the same treatment under the law as fellow citizens here," she told CNN after the news conference. "But they are American citizens, they deserve all the support that the federal government is capable to provide, and these are American citizens who go to war and fight for this country. They shed blood for the freedoms we enjoy in this country."

On Monday, a group of Democrats in the House -- including some Hispanic Caucus members -- sent a letter to House Natural Resources Committee Chairman Rob Bishop requesting an investigation into the Trump administration's response to Hurricane Maria's devastation in Puerto Rico, specifically citing the study.

"We therefore respectfully request that our Committee conduct a hearing before the August recess to properly evaluate this newly-available information as well to assess the urgent needs that remain in Puerto Rico," the letter read.

It noted the upcoming hurricane season as another reason to prepare for the hearing.

Ranking member Raul Grijalva and Rep. Ruben Gallego, as well as 12 others on the committee, signed the letter that was dated Monday.

The chairman's office responded to CNN's request for comment Wednesday, saying he has "committed to holding a hearing this July on energy solutions and recovery efforts in Puerto Rico post Hurricanes Maria and Irma."

Rep. Jenniffer González Colón, who represents Puerto Rico in Congress, sits on the committee but did not sign the letter. She did not respond to CNN's request for comment.

FEMA spokesperson Jenny Burke defended the agency's response to Hurricane Maria in a statement.

"Last year's hurricane season was historic, but so has been the effort by FEMA and our numerous federal, state and local partners," she said to CNN in a statement. "The insinuation that federal response has been lacking is absurd. FEMA has and will always work tirelessly to support state, local, tribal and territorial partners to respond to and recover from disasters."

Trump visited FEMA Headquarters in Washington for a briefing Wednesday to discuss preparedness ahead of the 2018 hurricane season on Wednesday, which officially began on June 1.

This story has been updated to include response from a FEMA spokesperson.