Investigators have been quietly seeking information in recent months about decision-making by DA Cy Vance Jr. and his staff, sources with knowledge of the undertaking said.

The queries are centered on how things are handled in the office and who the major players are, the sources said. The FBI interest grew out of revelations that investigations were closed once lawyers representing the bigwig suspects made hefty donations to Vance’s campaign coffers, sources said.

The team has asked about current and former high-level staff members and their relationships to private law firms and outside agencies, sources said. Investigators are considering whether undue influence was at play.