The US Department of Homeland Security on July 5 arrested Roman Valerevich Seleznev, the son of a Russian lawmaker, for what it said were computer crimes carried out from 2009 to 2011.
Russia has responded by this week accusing the United States of violating a bilateral treaty and "kidnapping" the Russian, who has been accused of hacking into US retailers' computer systems to steal credit card data.
The 30-year-old's father Valery Seleznev, a deputy in Russia's lower house, said in a statement he "intends to take all necessary steps to protect his lawful interests."
Roman Seleznev was apprehended in an airport in the Maldives, the Russian Foreign Ministry said.
"We consider this as the latest unfriendly move from Washington," it said in a statement on its website.
"This is not the first time the US side, ignoring a bilateral treaty ... on mutual assistance in criminal matters, has gone ahead with what amounts to the kidnapping of a Russian citizen."
In Washington, US State Department spokeswoman Jen Psaki disputed the Russian Foreign Ministry description of the matter, saying, "certainly, no kidnapping took place."
Seleznev was indicted in Washington state in March 2011 on charges including bank fraud, causing damage to a protected computer, obtaining information from a protected computer and aggravated identity theft, the US agency said in a statement.
The indictment said Seleznev hacked into websites ranging from those run by the Phoenix Zoo, a branch of Schlotzsky's Deli and many other small restaurants and entertainment venues around the country.
Relations between Russia and the United States are at a low ebb in Vladimir Putin's third term as president, with the former Cold War enemies divided over the conflicts in Syria and Ukraine as well as on human rights, democracy and defence matters.