China's foreign ministry on Monday nevertheless asked for a full explanation.
On Friday, a journalist at PC Mag sent out a tweet of a photo of a package along with a note reading: "Parcel returned by FedEx, due United States government issue with Huawei and China government".
Back in May, two parcels sent via FedEx destined for Huawei addresses in Asia were diverted to the United States.
The U.S. Commerce Department has banned a number of Chinese firms in recent weeks from buying sensitive U.S. technology.
"We realized when we reached a certain level there would be competition, but it didn't occur to us the USA government would be so determined to take such extreme measures against Huawei", Ren said.
FedEx on Monday hit US Department of Commerce with a lawsuit saying it's been forced to "police the millions of shipments" it transports each day by the department's trade blacklist - which includes embattled Chinese phone maker Huawei. Theoretically, FedEx says, the law requires FedEx to determine whether any package violates the law by shipping USA technology to a proscribed entity.
FedEx apologised for the incident.
A statement by the delivery firm said the restrictions placed "an unreasonable burden on FedEx to police the millions of shipments that transit our network every day" or face heavy fines.
Huawei, which said it was reviewing its relationship with FedEx after the mishandling of its packages earlier, did not immediately respond to a Reuters request for comment on Sunday.
In response to the package incident, Huawei Facts accused FedEx of having a vendetta against it. The Chinese government's reaction was the glitch was not a mistake. FedEx would not say where.
Right now, FedEx in a very hard position, walking a tightrope between the two largest economies in the world and trying not to lose business from either.
China announced last month it would create its own blacklist of "unreliable" companies and individuals, which could target USA and worldwide firms that have cut off supplies to Huawei.