Rudy Giuliani is urging an investigation into Joe Biden’s suspected conflicts of interest. The president’s attorney took to Twitter Thursday, saying Biden could have been involved in a corruption conspiracy in Ukraine.

Giuliani urged a probe into Biden’s role in meddling with Ukraine’s internal affairs back in 2016. This comes after Biden confessed he threatened, on behalf of the Obama administration, to withhold a credit line to Ukraine unless it dismissed its top prosecutor at the time.

The Ukrainian official was leading a corruption probe into a company in which Biden’s son, Hunter, was a board member.

Giuliani said Biden’s conflicts of interest are apparent, but his alleged involvement in transnational corruption must be looked into as well.

https://t.co/FNVj16Hf10 via ⁦@nytimes⁩. Biden conflicts are too apparent to be ignored and should be investigated quickly and expeditiously. But the more important question is how deep and how high did the alleged Ukraine conspiracy go?

— Rudy Giuliani (@RudyGiuliani) May 2, 2019