The Russian economy has been hit by multiple headwinds, and a potential "sanctions bill from hell" by the U.S. could make things worse, according to a Moscow-based investment bank.

Facing sanctions threats and caught in an emerging markets rout, Russian stocks — measured by the RTS index — have fallen 11.4 percent this year. Its currency, the ruble, has depreciated by around 20 percent against the U.S. dollar since the start of 2018.

The challenging business climate has led to some companies suspending their plans, Petr Molchanov, head of investment banking for Russia at Renaissance Capital, said on Wednesday.

"A number of high-profile equity issuance and issuers have put things on hold, definitely. So, there is a pipeline of high quality ECM (equity capital market) deals from Russia waiting for slightly better conditions, slightly more certainty but there is a supply of deals for sure," Molchanov told CNBC's Geoff Cutmore at the Eastern Economic Forum in Vladivostok, Russia.

Activity in the mergers and acquisitions space also "doesn't look bad at all," said Molchanov. The investment banker didn't provide details on those deals, but added that he wouldn't describe Russia's capital markets as "healthy" or "strong."

A "sanctions bill from hell" could hurt the Russian economy further, he said. The term was first used by Republican U.S. Sen. Lindsey Graham, who spearheaded the bill that includes harsh measures such as preventing American entities from purchasing Russian sovereign debt.

"I think it will be quite detrimental," Molchanov said. "But I think nothing has become completely, completely dangerous and damaging for the country which has been living in these conditions for quite some time and handling that quite successfully."

Correction: This article has been updated to reflect that Petr Molchanov is the head of investment banking for Russia at Renaissance Capital.