Christopher Rennard, who now sits in the House of Lords as Baron Rennard, denies the charges, The Daily Telegraph reported. The newspaper said it has learned Jonny Oates, chief of staff to the current leader, Deputy Prime Minster Nick Clegg, did not take any action when he was alerted to the alleged harassment.
This week women who say Rennard harassed them went public on Channel 4.
Party officials now say they are investigating the charges against Rennard and examining their procedures for dealing with such cases.
Rennard, 52, worked for the party for many years as an organizer and then as chief executive. He resigned in 2009.