Toxic debts racked up by banks and insurers could spiral to $4 trillion, new forecasts from the International Monetary Fund are set to suggest, British daily The Times reported on its website without citing sources.

The IMF said in January that it expected the deterioration in U.S.-originated assets to reach $2.2 trillion by the end of next year.

But it is understood to be looking at raising that to $3.1 trillion in its next assessment of the global economy, due to be published on April 21, the newspaper reported.

In addition, it is likely to boost that total by $900 billion for toxic assets originated in Europe and Asia, the Times said.

(Reporting by Hugh Lawson; Editing by Jan Dahinten)