Two senators are calling for the resignation of the Department of Homeland Security's deputy inspector general.

Sens. Ron Johnson, R-Wis., and Claire McCaskill, D-Mo., said Charles K. Edwards improperly delayed responding to a Senate subcommittee's investigation of his conduct.

McCaskill is chairman and Johnson is the ranking minority member of the Senate's subcommittee on financial and contracting oversight.

In an Oct. 30 letter to Edwards, the senators said the subcommittee has received only partial responses to 16 document requests, while five of its requests remain unanswered.

"Your office has failed to provide certain relevant, accessible documents specifically identified by subcommittee staff," the senators said in the letter.

The documents were sought in response to multiple allegations of misconduct by Edwards.

Cause of Action, a nonprofit watchdog group, called for Edwards' removal in a July 2013 letter to President Obama that described the allegations, including improper travel to South Florida in 2010, favoring his spouse for positions in government and failure to comply with the Freedom of Information Act.

"The bipartisan call for deputy IG Edwards to resign echoes what Cause of Action asked of the president back in July," said Dan Epstein, president of COA.

"Our own investigation exposed the potential misconduct, abuse and even violation of federal law by Edwards, leading to our request that he be removed from his position," he said.

Epstein also criticized what he called "the complete lack of transparency and accountability at DHS regarding Edwards conduct.

View the letter from Cause of Action here.