WASHINGTON -- The Obama administration imposed sanctions Thursday on a Greek ship owner and his business partners, alleging they are helping Iran skirt global sanctions on sales of its oil.

But the ship owner, Dimitris Cambis, countered that the United States was actually doing the dirty work for rivals who want his lucrative Iranian natural gas concessions.

“They want to connect my name with sanctions in order to deter me,” Cambis told McClatchy in an interview that was rare primarily because businesses targeted by anti-Iran sanctions don’t often make themselves available for questions. “There are very big boys that are interested in what we have.”

“That’s clearly not the case,” said Treasury Department spokesman John Sullivan, pointing to the agency’s news release, which detailed the scheme.

Under the scheme, Treasury alleged that Cambis, through the Greek company Impire Shipping Ltd., purchased large, aging tankers on behalf of the National Iranian Tanker Co., then filled those tankers at sea with oil supplied by the National Iranian Oil Co. The Treasury did not say where the oil was taken or who was suspected of purchasing it.

One such transfer occurred in December off Khor Fakkah in the United Arab Emirates, the Treasury Department said. It identified eight tankers owned by Campis involved in the transactions. Also targeted Thursday were four companies in the United Arab Emirates that did business with Campis.

“I think they have a very big imagination,” Campis told McClatchy by phone from Athens. “I think they have been misguided by my involvement in the (natural) gas business.”

Pressed for details, Campis said he enjoys a concession from Iran to carry 1.06 trillion cubic feet of natural gas, a concession he cannot exploit because of current sanctions but one day expects to put to use. Iran is one of the few nations that can convert natural gas to liquid form.

“They want us to refrain from exporting the Iranian gas, when it is allowed,” Campis said. “We have the rights.”

Campis did not specify whether he believed the government was acting on behalf of U.S.-based energy companies or rivals in the region.

Campis can challenge the sanctions under the Administrative Procedures Act but can only see unclassified information.

“It’s too early to decide, but definitely I am not alone and I believe in U.S courts and U.S. justice, and we’ll decided in due time,” he said.

As to previously published allegations that he helped Iran skirt global oil sanctions with sales to China, Campis insisted there is no surprise that he does business with China.

“All of our ships, they travel from the Arabian Gulf to China, and our charter parties are major Chinese oil companies,” he said.

Oil is the lifeblood of the Iranian economy, and Iran is the second largest exporter in the Organization of Petroleum Exporting Countries, the cartel of oil-exporting states. In an effort to curb Iran’s nuclear program, the United States has sought to starve Iran of oil money.

Despite the sanctions, countries reported importing 1.28 million barrels per day of Iranian oil in February, up from 1.13 million barrels per day in January, the Paris-based International Energy Agency reported Wednesday. The report said “foreign middlemen” used overhauled tankers bound for scrap yards to move Iranian oil to China.

“New U.S. sanctions implemented in February, which bar Iran from repatriating earnings from its oil exports, appear not to have had an impact on February shipments,” the IEA said.