"It appears a prima facie case for retaliation by the Navy against Captain Crozier may have been established," the letter said. "We urge you to open an investigation into this matter as soon as possible."
The congressmen said in the letter that the investigation must determine if Modly's actions were appropriate or legal.
On Thursday, Navy Acting Secretary Thomas Modly announced he made the decision to remove Crozier because he improperly sent an email about his concerns regarding the COVID-19 outbreak on the ship using channels that are not secure to convey confidential information.
Although Crozier did not leak his message to the press he did send it to at least 20 recipients who may have leaked it.
There are about 114 sailors on the Roosevelt who have tested positive for the novel coronavirus and more cases are expected, according to Modly.
