A federal judge says Sen. Ted Stevens can probe the mental health of the government's star witness in the corruption trial against the Alaska icon.

U.S. District Judge Emmet Sullivan says government witness Bill Allen must turn over his medical records dealing with his 2001 motorcycle accident.

Allen suffered brain damage in the accident, but the government says it affects only his speech, not his memory.

Stevens' lawyers want the records to determine if Allen's testimony against Stevens can be trusted.

Stevens is accused of lying in Senate financial disclosure records about hundreds of thousands of dollars in gifts and home renovations he received from VECO Corp. Allen, who founded VECO, has pleaded guilty to bribery and corruption charges.