A federal grand jury has heard testimony from witnesses in the FBI’s corruption investigation of Las Vegas City Councilman Ricki Barlow. The investigation has focused on allegations the councilman received kickbacks from campaign funds he steered to consultants. Witnesses first appeared before the grand jury a few months ago, and the nearly 3-year-old investigation remains active, a knowledgeable source said. It is unclear how many witnesses have testified and whether federal prosecutors might be close to filing charges against Barlow.