Rep. Henry Waxman (D-Calif.) recently renewed his request that the House Committee on Energy and Commerce investigate the role of Koch Industries in the Keystone XL pipeline.

Waxman, the ranking minority member of the committee, made his request in a letter to committee chairmen Fred Upton (R-Mich.) and Ed Whitfield (R-Ky.).

Waxman first asked for an investigation in May, when the committee was holding hearings on the Keystone XL, a controversial Canada-to-Texas oil pipeline that would allow as much as 830,000 barrels a day of a particularly dirty form of oil, locked up in Alberta’s tar sands, to reach refineries in the Gulf of Mexico.

The controversy over the Kochs and the pipeline was sparked by an InsideClimate News report from February. That analysis, also published on and later cited by various news organizations, found that Koch Industries is deeply involved in the Canadian oil sands trade and is well positioned to benefit if more heavy crude is exported to the United States. The company denied the report, and Waxman subsequently made his own inquiries.

“When I first raised this issue in May, representatives from Koch denied any interest in the pipeline and Chairman Upton called the idea that there could be a link between Koch and the pipeline an ‘outrageous accusation’ and a ‘blatant political sideshow,'” Waxman wrote in his letter. “Recently, however, I have become aware of evidence that appears to contradict the assertions of the Koch representatives and Chairman Upton.”

Read the rest of this cross-post from InsideClimate…