A Senate panel is said to be looking into warnings by a former trader at JPMorgan Chase (JPM) months before his bets ballooned into a $6 billion loss for the company.

Hesitation expressed by Bruno Iksil, whose outsize bets earned him the moniker the "London Whale," is among areas being examined by the Senate Permanent Subcommittee on Investigations, the Wall Street Journal reported late Thursday.

The subcommittee, which has been probing last year's trading loss at the nation's biggest bank by assets, is said to be reviewing emails sent by Iksil to superiors, according to the publication, which cited unnamed people familiar with the probe.

An internal report on the incident that was released on Jan. 16 by the company cites an email by an unnamed trader who warned colleagues in January 2012 that his bets were "becom[ing] scary" and that the bets would expose JPMorgan to "larger and larger drawdown pressure" as a result.

The bank redacted names from the emails cited in its report.

The subcommittee, which is headed by Sen. Carl Levin (D-Mich.), also reportedly is looking into whether JPMorgan failed to disclose information to the Office of the Comptroller of the Currency and whether the OCC failed to inquire sufficiently about the company's processes for managing risk.

According to the Jan. 16 internal report, by last February a series of losses spurred the unnamed trader to ask to meet with Ina Drew, JPMorgan's former chief investment officer. At the meeting, the trader reportedly told Drew the bank could lose another $100 million and that it was possible the bank had misplaced its bets. For her part, Drew "appeared not to be overly concerned" about the loss, the report found.

A subcommittee spokesman declined to comment, while a JPMorgan spokesman did not respond to a request for comment. Drew could not immediately be reached.

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