Federal prosecutors have subpoenaed documents as part of a grand jury investigation of state Senate Majority Leader Dean Skelos.

A source with direct knowledge of the subpoenas says they were sent out in the past week, to eight of the nine state senators from Long Island —but not Skelos himself.

The source says the subpoenas asked for documents dating back to January 1, 2013.

According to the source, the documents involved focus on the state budget, and four or five different companies.

They also focus on Skelos's son, Adam.

Neither Skelos nor his son have been officially accused of wrongdoing.

Federal prosecutors have been targeting Albany corruption in recent months.

Their most high-profile target has been former Assembly Speaker Sheldon Silver, who is now facing corruption charges.

He's accused of taking millions in bribes and kickbacks.