Rep. Dana Rohrabacher (Image credit: Chip Somodevilla/Getty Images)

MOSCOW - A delegation of American lawmakers will travel to Russia next week in part to investigate last month's Boston Marathon bombings, ABC News has learned.

The group, led by Rep. Dana Rohrabacher, R-Calif., wants to find out why a 2011 Russian request that the United States investigate Tamerlan Tsarnaev, one of the suspected Boston bombers, did not raise more red flags.

The Russians offered a vague warning that Tsarnaev planned to link up with extremist groups abroad, but an FBI investigation yielded no evidence to support those claims at the time. The lawmakers also want to know why subsequent U.S. requests for additional information about Tsarnaev went unanswered by the Russians.

"If there was a distrust, or lack of cooperation because of that distrust, between the Russian intelligence and the FBI, then that needs to be fixed and we will be talking about that," Rohrabacher, the chairman of the House Committee on Foreign Affairs' Subcommittee on Europe, Eurasia and Emerging Threats, told ABC News by telephone.

"Our goal is to use Boston as an example, if indeed there was something more, that should've been done that wasn't because of a bad attitude," Rohrabacher added.

Rohrabacher said he hoped to use the trip to repair lingering mistrust between the former Cold War rivals. With that in mind, the lawmakers will also visit the Russian space center at Star City, outside Moscow, to discuss increasing cooperation between the Russian and U.S. space programs.

"There's no reason for us to be in the Cold War attitude anymore," Rohrabacher, a former speechwriter for President Reagan, said.

The lawmakers plan to meet political and security officials, including counterterrorism officials, during their week-long visit to Russia. They are also considering a trip to Dagestan, the restive region in Russia's North Caucasus, where Tsarnaev spent six months last year and where investigators are digging into contacts he may have had with extremists and militants.

The other members of the congressional delegation include Reps. Michele Bachmann, R-Minn; Steve King, R-Iowa; Paul Cook, R-Calif.; Steve Cohen, D-Tenn.; and William Keating, D-Mass., who is the ranking member on the Subcommittee on Europe, Eurasia and Emerging Threats.

Several weeks ago Keating sent a member of his staff to Russia to investigate whether Tsarnaev had met with any extremists or militants in Dagestan. The staff member could confirm, from nongovernmental sources, reports from ABC News and elsewhere that Tsarnaev had been in touch with at least two such individuals, Mahmoud Mansour Nidal and William Plotnikov, during his time there.

According to the staff member, it was Plotnikov who first mentioned Tsarnaev's name to Russian investigators during an interrogation. That may have been the reason Tsarnaev first came under scrutiny. Both Nidal and Plotnikov were killed in police raids last year.