Chinese diamond firm Anjin failed to remit revenue from its operations in Zimbabwe's controversial Marange fields in the first quarter of this year, Finance Minister Tendai Biti said on Thursday.

"We have not received a single cent from Anjin, yet Anjin is seven times bigger than some of the other (diamond) companies," Biti told reporters giving his monthly fiscal statement.

Anjin is in a joint venture with the Zimbabwe government, as are three other firms.

Biti said there were suspicions the funds were funnelled elsewhere, outside the government central coffers.

"Clearly, we fear as the ministry of finance that there might be a parallel government somewhere in respect of where these revenues are going, and are not coming to us.

"There is opaqueness and unaccountability surrounding our diamonds."

Anjin along with Diamond Mining Corporation, Mbada and Marange Resources are mining the gemstones in Zimbabwe's eastern Marange area, where activists have reported gross rights abuses.

Zimbabwe government owns a 50 percent stake in all the four companies.

Biti said Anjin's failure to pay in proceeds from its diamond sales could impact negatively on Zimbabwe's $4-billion budget for 2012 where at least $600 million was projected to come from diamond sales.

Total revenue collections for the first quarter of 2012 stood at $287.9 million against a target of $320.2 million, with the shortfall blamed on "underperformance of diamond revenue."

"Diamond revenues have been underperfoming since January to 2012, with only $30.4 million remittances received for the period January to March 21, 2012," he said. The target was $122.5 million.

Biti said he has complained to leaders in the power-sharing government over the diamond revenue shortfall.

He said Zimbabwe's economy, which went into a tailspin amid a political crisis before the creation of unity government three years ago, continued to recover with gains in the mining, manufacturing and energy sectors.

Inflation will remain in single digits but might be higher than anticipated if revenue shortfalls continue, said Biti.