TULSA, Okla. (AP) - Unsecured creditors of a Tulsa energy company want to see documents about SemGroup LP's energy trading and cash transfers in the days and weeks leading up to its bankruptcy declaration.

The creditors have told a federal judge they are interested in seeing documents with information that includes ``eve-of-bankruptcy transfers, futures and options trading activities, and insider and affiliate transfers.''

SemGroup, an oil and asphalt transportation and storage provider, filed for Chapter 11 protection on July 22 after apparently losing a reported $2.4 billion in the oil futures markets.

A U.S. trustee overseeing SemGroup's case already has asked the bankruptcy judge to appoint an examiner to investigate the company's collapse.