Thanks to Bruce Littleboy for pointing me to this complete translation of Hayek’s 1981 interview with the (pro-Pinochet Chilean) newspaper El Mercurio in which he stated
Personally I prefer a liberal dictator to democratic
government lacking liberalism.
As the interview makes clear, Hayek supports the Pinochet dictatorship, on the assumption (correct in the end) that it would eventually give way to a more liberal regime. Of course, many supporters of dictators make this assumption and all dictatorships, like all governments, pass away sooner or later.
Plenty of people have made worse political mistakes than backing Pinochet, most obviously those sections of the left who supported Stalin, Mao and their lesser accomplices. Still, the fact that both the Mont Pelerin society and leaders of the free-market right like Thatcher and Reagan gave their enthusiastic support to this mass murderer should be remembered when they, and their followers, try to claim the moral high ground as against the moderate left.