The conservative watchdog group Judicial Watch sued the Environmental Protection Agency on Wednesday to disclose all communications made by EPA officials using special encryption software to undermine President Trump's environmental agenda.

The group filed a Freedom of Information Act lawsuit in district court in Washington, seeking all "communications sent or received by EPA officials who may have used the cell phone encryption application 'Signal' to thwart government oversight and transparency," according to a statement.

Using the app could prevent federal agencies from complying with Freedom of Information requests because it bypasses the use of government servers. The group said the agency has a history of using personal communications devices to conduct official business, which is undermining its ability to fulfill its obligations under federal disclosure laws.

The lawsuit was filed after the EPA failed to respond to Judicial Watch's Feb. 3 FOIA request seeking "any and all work-related communications" sent to or from EPA officials using the Signal app from Feb. 3, 2016, to the present, according to the group.

Signal allows anonymous, encrypted communications between the parties that use it on smartphones. Reporters have used the app to solicit government sources to communicate to them about changes taking place in the Trump administration within EPA and other agencies.

The Judicial Watch effort is in response to a Politico article titled, "Federal workers turn to encryption to thwart Trump."

"Given EPA's checkered history on records retention and transparency, it is disturbing to see reports that career civil servants and appointed officials may now be attempting to use high-tech blocking devices to circumvent the Federal Records Act and the Freedom of Information Act altogether," said Tom Fitton, president of the group.

"This new lawsuit could expose how the anti-Trump 'deep state' embedded in EPA is working to undermine the rule of law," Fitton said. "Let's hope the Trump administration enforces FOIA and turns over these records."