Huawei has been accused of indirectly attempting to supply kit to Iran’s largest mobile operator in an apparent breach of US trade sanctions against Iran.

According to documents seen by Reuters, the Chinese vendor offered to sell at least EUR1.2 million of embargoed Hewlett-Packard computer equipment to MCI in late 2010. The approach was said to be made by one of Huawei’s “major local partners,” a company called Skycom Tech.

The deal did not go ahead – though the allegations are likely to sour already frosty relations between Huawei and the US government.

The vendor was recently criticised by the US House Intelligence Committee for failing to “provide evidence to support its claims that it complies with all international sanctions or US export laws.”

In a statement to Reuters, Huawei said the proposal handed to MCI was merely a “bidding document.”

“Huawei’s business in Iran is in full compliance with all applicable laws and regulations including those of the UN, US and EU,” the firm added.

The contract would have doubled the capacity of MCI’s billing system for prepaid customers. The proposal noted that MCI was “growing fast” and that its current system, provided by Huawei, had “exceeded the system capacity” to handle 20 million prepaid subscribers. It adds that the HP computer servers were an integral part of the “Hardware Installation Design” of the project.

In October, Reuters reported that another Iranian partner of Huawei tried to sell embargoed US antenna equipment to Iran’s second largest mobile operator, MTN Irancell, in 2011 – a deal the buyer ultimately rejected.

The news agency ran several stories last year exposing how China has become a “backdoor” for Iran to obtain embargoed US computer equipment.