A prominent lawmaker is urging Congress to investigate how pervasive hazing is in the military after shocking allegations that some drill instructors abused recruits and even fellow DIs at the Marine Corps' storied training ground.

"It is incumbent upon us in our oversight role to determine the extent to which this is a systemic problem and make sure the military is doing everything in its power to prevent cases like this from happening again," Rep. Jackie Speier, D-Calif., wrote in a letter Friday to the chairman and ranking member of the House Armed Services committee.

Speier wrote she is concerned about media reports "depicting a culture of hazing and abuse" at Marine Corps Recruit Depot Parris Island, South Carolina, where recruit Raheel Siddiqui died in March when he fell nearly 40 feet in a barracks stairwell.

Siddiqui, 20, was assigned to the 3rd Recruit Training Battalion at the time. A command investigation into his death found that drill instructors in the battalion slapped and choked recruits. Siddiqui had threatened to kill himself five days before his death, saying his drill instructors were hitting him, according to the investigation.

Up to 20 Marines at Parris Island are under investigations for allegations of abuse. These allegations stem from the Siddiqui case and other reported incidents. As of Friday, none of the Marines under investigation has been charged or received punishment or disciplinary action.

"Unfortunately, for all the tragic examples, we still lack a clear understanding of hazing and the military’s response," Speier wrote on Friday. "According to the [Government Accountability Office], the Department of Defense does not even know the extent of hazing in the organizations because they have not conducted an evaluation of its prevalence, nor developed a unified system to track the instances of hazing department-wide."

Holding a congressional hearing into hazing in the military would provide lawmakers with a greater insight into the problem and allow Defense officials to explain the actions they are taking to prevent further abuse, Speier wrote.

"We are deeply concerned about this issue," a spokesman for House Armed Services Democrats said Friday. "Hazing has no place in our armed services. We have been conducting oversight on it, and additional oversight would be very welcome."

The House Armed Services Committee has held hearings about military hazing in the past, said a spokesman for Rep. Mac Thornberry, R-Texas, who chairs the committee.

"Chairman Thornberry will certainly consider them as part of our oversight program on this important issue going forward," said Claude Chafin.

The Marine Corps has already taken several actions to prevent the type of hazing alleged to have occurred at Parris Island, including preventing a Marine from being able to train recruits if he or she is under investigation.

One of Siddiqui’s drill instructors had been accused of hazing another Muslim recruit. After making the recruit exercise in the shower, the drill instructor allegedly ordered him to get in to a commercial dryer and turned it on several times while making disparaging comments about his religion, an investigation found. At one point, the drill instructor asked the recruit if he was part of the Sept. 11, 2001, terrorist attacks.

Marine Corps Commandant Gen. Robert Neller has said most drill instructors at both the service’s East and West Coast training depots are training recruits properly.

"Recruit training is designed to be tough and demanding,"

. "That’s why young men and women join the Marine Corps, because they want to be challenged and tested. I have every confidence that the drill instructors that are out there both at Parris Island and San Diego understand that."