LAS VEGAS — The House Energy and Commerce Committee leadership on Tuesday ordered Federal Communications Commission chairman Kevin Martin to retain documents and emails and refrain from retaliating against agency workers who might assist the panel’s investigation of Martin’s management practices.

“To be clear, no such records shall be destroyed, modified, altered, deleted, removed, relocated, or otherwise negligently or intentionally handled so as to make them inaccessible to the committee,” panel chairman John Dingell (D-Mich.) said in a letter to Martin signed by the panel’s top Republican, Rep. Joe Barton (Texas).

Based on unspecified complaints about Martin’s control of the FCC, Dingell has launched a full-scale investigation to “address a growing number of allegations received by the committee relating to management practices that may adversely affect the agency’s operation.”

Dingell, who has not announced a public hearing, has bipartisan support for the probe, said Barton, who attended the 2008 International CES here on Tuesday. Barton declined to comment when asked to relate the worst allegation about Martin that has been brought to his attention.

“I don’t want to get into that,” Barton said. “As the hearing agenda is proposed, you will see what the hearing agenda is.”

The cable industry has complained that Martin has targeted the industry for regulatory punishment because cable operators and programmers refuse to sell channels on on a la carte basis, Martin’s pet cause.

Martin had to back down in November when an FCC majority accused him of manipulating data. And the start of the FCC’s open public meeting that month was pushed back almost 12 hours, with votes and debate occurring in the dead of night.

Dingell’s panel intends to interview FCC staff and others prior to the hearing. The letter instructed Martin to alert all FCC employees that they have a right to cooperate free from retaliation.

“It is against federal law to interfere with a congressional inquiry,” the letter said.

The letter order Martin and his staff to ‘”preserve all electronic records, including work email and personal email communications relating to official work of the Commission, and calendars and schedules of all employees (and paper copies and versions of those records).”

Martin addressed reporters at the 2008 International CES a few hours before Dingell released the letter.