Barack Obama’s administration has been accused of undermining an investigation into the terrorist group Hezbollah in order to secure its nuclear deal with Iran.

The former US president’s team was said to have put “roadblocks” in place to slow the investigation amid fears it would undermine negotiations with the regime.

The claims were made in an article by Politico, the politics website, and relate back to when Mr Obama was in the White House.

The allegations are linked to Project Cassandra, a campaign launched in 2008 by the Drug Enforcement Administration against Hezbollah.

It was said to have detailed how the Iranian-backed terror group morphed from a political and military organisation into an “international crime syndicate”.

In particular agents were said to be investigating an alleged $1 billion-a-year funding stream from drugs, weapons trafficking, money laundering and other crimes.