The Brazilian real has fallen a similar amount, hitting 2.4282 to the dollar, a rate unseen since March 2009.

The Turkish lira has fallen by around 10 percent since a February peak, with the central bank raising its overnight rate on Tuesday to relieve short-term speculation on the currency.

The fall in Thailand's baht, Indonesia's rupiah, and Malaysia's ringgit has also picked up speed in recent weeks as speculation has intensified about the Fed scaling back stimulus.

Recent improvement in US economic data has convinced many investors that the Fed will in September begin reducing from $85 billion per month the stimulus it injects into the economy.

Much of the money the Fed injected into the US market seeped abroad, in particular to emerging economies, as investors sought out higher returns.

"Asian markets have benefited hugely on easy Fed cash over the years but with a reduction in liquidity due to tapering to contend with, there is growing concern that capital outflows from emerging markets will rapidly accelerate," said analyst Ishaq Siddiqi at trading firm ETX Capital.

"This has tarnished the investment case for the emerging market space as investors would rather pile into growth-focused assets geared to the US economic recovery," he added.

However, analyst Michael Hewson at CMC Markets believes this is only half the story.

"...the growth slowdowns being experienced in those markets have forced investors to look more carefully at the structural problems that are facing those particular economies, with India and Brazil in particular in the firing line, as growth slows and inflation rises," said Hewson.

The International Monetary Fund warned last month that China and other emerging economic powers now face the risk "of a longer growth slowdown."

It said the Fed's unwinding of its massive monetary policy stimulus could trigger sustained capital outflows from emerging markets, which it said have generally been hit hardest by recent increased financial market volatility and rising interest rates.

Several central banks have acted to stem the slide of their currencies and the increase in inflation this implies.

Turkey's and India's central banks have intervened in the currency markets, with India also slapping controls on foreign currency outflow.

However, Neil Shearing at Capital Economics said: "We suspect that policymakers are now more tolerant of weaker exchange rates than in the past."

He noted that foreign currency debt burdens are much lower than a decade ago, meaning that weaker currencies do not pose the same risk.

A weaker currency can help a country regain international competitiveness as it makes exports cheaper.

Brazil has complained several times that monetary stimulus by advanced countries was in fact a currency war that had harmed it by leading to an appreciation of the real. (AFP)