SAN DIEGO -- It appears a federal grand jury is wrapping up its investigation into alleged influence buying at San Diego's City Hall, 10News reported.

Two former strip club employees -- who were first subpoenaed on July 11 -- were due to testify Friday about campaign contributions they made to members of the San Diego City Council. However, Vincent Tomasello and Richard Tomasello were excused instead.

Last week, federal agents testified about the two-year investigation into contributions the council members received from strip club owners.

Sources familiar with the grand jury process said agents are often the last to testify because their testimony can tie up loose ends and summarize the prosecution's case.