Liu's ex-campaign treasurer, Jia "Jenny" Hou, and former Liu fundraiser Xing "Oliver" Wu Pan are facing federal charges of conspiring to break campaign finance laws.

WSJ: Trial opens for aides of NYC mayoral hopeful

Mr. Liu said he believed in the innocence of Jia "Jenny" Hou, his 26-year-old former campaign treasurer, who was convicted of attempted wire fraud, obstruction of justice and making false statements to federal law-enforcement agents.

WSJ: New York City Comptroller Liu Defends Campaign

On Thursday, Ms. Lee testified for a second day in Manhattan federal court at the trial of Jia "Jenny" Hou, Mr. Liu's former campaign treasurer, and Xing Wu "Oliver" Pan, a longtime campaign contributor.

WSJ: City Comptroller John Liu Stands By His Aide

In February 2012, Mr. Bharara's office charged Jia Hou, campaign treasurer for New York City Comptroller John Liu, a mayoral candidate, with fraud and obstruction of justice.

WSJ: Bharara Sees 'Pervasive' Corruption