The Minister for Justice should consider revoking passports issued to two non-nationals who are wanted on criminal charges abroad, according to the Labour Party.
A businessman from Britain and another from the Czech Republic wanted on separate charges of fraud involving hundreds of millions of euros are thought to hold Irish passports issued under the "passports-for-investment" scheme.
Labour's justice spokesman, Mr Joe Costello, said although the passports were probably issued in good faith, their reputation could be compromised internationally if they continue to be held by fugitives.
He said the situation "may create an impression that Ireland is some sort of safe haven for international crooks".
Mr Costello urged Mr McDowell to examine the possibility of revoking the passports but said that because the "passports-for-investment" scheme was not created on a statutory basis there was no "specific provision" for their withdrawal.
Multi-millionaire Mr Victor Kozeny - nicknamed "the Bouncing Czech" and the "Pirate of Prague" - was last week charged with fraud over an alleged scam involving the privitisation of state-owned companies in the Czech Republic following the collapse of communism in the early 1990s.
His company, Harvard Investment Funds, was given billions of crowns by Czechs to invest in the new ventures, but Mr Kozeny and partner Mr Boris Vostry allegedly left the country without making the investments.
Both are considered fugitives by Czech authorities, and Mr Kozeny is understood to be living in the Bahamas under an Irish passport issued in 1995.
In a recent statement, Mr Kozeny compared the charges to the "burning of witches at the stake". "As a foreign citizen I will use all my rights against this political trial," he added.
Mr Vostry described the charges as "scandalous".
The second case involves Briton Mr Sheridan Cox, who is being prosecuted by Taiwanese authorities in connection with a boiler room scam believed have netted more than €700 million.
The prosecutors are investigating an investment management company, Mendes Prior, which allegedly swindled hundreds of millions of euros from South African investors in particular. The alleged scam also targeted investors in Zimbabwe and Botswana.
Mr Cox is also wanted in several European countries for a similar investment scam in which non-existent shares were sold to unsuspecting investors. He has also been convicted in his absence for a fraud scandal in Belgium.