After months of investigating, federal prosecutors in Maryland have not produced enough evidence to bring charges, according to four people familiar with the investigation.

The federal mortgage fraud investigation against Democratic Sen. Adam Schiff, one of President Donald Trump’s chief political foes, has stalled, according to four people familiar with the investigation.

After months of investigating, the federal prosecutors in Maryland leading the probe have not produced enough evidence to bring charges, these people said.

One of the sources, a federal law enforcement official, said the investigation “came to a standstill.”