Former world champion Damon Hill says Formula 1 should re-think plans to hold the Bahrain Grand Prix.
Hill backed the race after visiting the country on a fact-finding mission with motorsport boss Jean Todt in December.
But now he has told the Guardian: "What we must put above all else is what will be the penalty in terms of human cost if the race goes ahead.
"It would be a bad state of affairs, bad for F1, to be seen to be enforcing martial law to hold the race."
Last year's Bahrain Grand Prix was cancelled following civil unrest in February 2011 in which about 40 people were killed after government forces stormed a protest camp in the Gulf state's capital, Manama.
Unrest continues on an almost daily basis on the island and both opposition groups in Bahrain and human rights activists elsewhere have called for the race to be cancelled.
Hill said: "Looking at it today you'd have to say that [the race] could be creating more problems than it's solving.
"The protests have not abated and may even have become more determined and calculated. It is a worrying state of affairs."
The Bahrain race organisers held a lunch in London last week at which they argued that holding the grand prix would have an important unifying role in the country.
And F1 boss Bernie Ecclestone has said he has no doubts about holding the event, which is scheduled for 22 April.
The Formula 1 teams have so far said they trust the authorities to make the right decision, and senior representatives of Red Bull, McLaren, Mercedes, Williams and tyre supplier Pirelli all attended the lunch last week.
However, BBC Sport understands that the teams do privately have misgivings about the race, as do some sponsors, and some expect it to be cancelled at the 11th hour.
Hill said: "The view I gave after returning from the visit last year was based on my understanding of several factors; the substantial economic significance of the GP for Bahrain; that the report on the riots condemned the actions of the police and security forces, and that both sides were to take part in meaningful dialogue to resolve the problems peacefully.
"Under those conditions one could imagine the GP being a great fillip for a Bahrain on the road to recovery.
"However, with under three weeks to go, conditions do not seem to have improved, judging by the reports in our European newspapers, social media and on Al Jazeera TV.
"The recent meeting to garner support for the race as a unifying event was troubling insofar as it tried to represent the rioting in Bahrain as the result of bad press reporting and as a 'youth' issue.
"Promoting the race as 'Uniting Bahrain', whilst a laudable ambition, might be elevating F1 beyond even its own prodigious powers."
Hill emphasised he was not calling for the race to be cancelled - just for the F1 authorities to think about whether holding it was the right thing to do.
"I'm just saying we have to tread carefully," he said.
"I hope the FIA are considering the implications of this fully and that events in Bahrain are not seen as they are often sold, as a bunch of yobs throwing Molotov cocktails, because that's a gross simplification. If they believe that, they ought be more wary.
"You don't get 100,000 people risking their lives in protest for nothing."
The FIA, of which Todt is president, declined to comment.