Conventional wisdom these days suggest that the U.S. dollar remains a safe haven for investors compared to the euro, which is under considerable pressure due to the growing debt crisis facing Greece and a few other European countries. But at least one analyst contends investors shouldn't be so quick to assume these macroeconomic developments are necessarily good for the U.S. dollar.

Axel Merk of Merk Investments, thinks it’s the dollar, not the euro, that investors should be leery about.

In a report published Wednesday by Morningstar, Merk says that while Greece may have “rather serious issues,” investors “may want to take a closer look at their dollar holdings” for hidden “contagion risks.”

The biggest risk, he argues, is with money funds, which he says have been moving into riskier investments because of the low yields available on T-Bills.

While Merk doesn’t name names, he cites the example of two funds that Merk Investments analyzed. One, a large institutional money market fund with $74 billion in assets, was found to be 4.6% invested in commercial paper issued by BNP Paribas, a French bank with $7.2 billion worth of Greek bond holdings on its books. The other was a retail money market fund with $1.4 billion in assets, two-thirds of which Merk found were invested in U.S.-dollar-denominated commercial paper and other short-term debt instruments issued by European banks.

Merk says the euro lately has been rallying against the dollar because less money is being spent and printed in Europe than in the U.S.

Meanwhile, in the U.S., “the Federal Reserve may be actively working to weaken the dollar in order to spur economic growth," a tactic he said Federal Reserve Board Chairman Ben Bernanke has been doing “in both word and action.”

He suggests that a strong euro can survive any Greek debt crisis and adds, “What many don’t realize is that currencies of countries, or the Euro zone in this case, that don’t actively debase their currency may end up with a lot of pain, and less economic growth, but potentially a very strong currency.”