A MILITARY-STYLE semi-automatic rifle on its way to the Queensland Police Service has gone missing in the mail.

An investigation has been launched to find the Remington R4 carbine .223 after it was lost by a freight company dispatched by the company of arms dealer Robert Nioa.

The weapon, understood to have been sent months ago, was supposed to arrive in a remote part of Queensland but has mysteriously disappeared.

Mr Nioa confirmed that the freight company had lost the weapon but said he was unable to comment further about how and where it went missing or which organisation had been in possession of it.

"I can confirm there is a current and ongoing police investigation into the potential theft of the weapon," he said.

"I remain optimistic that the police will recover the weapon and charge whoever is responsible."

The Queensland Police Service spent almost $1 million buying 420 of the Remington R4 carbine .223 firearms with scopes for long-range vision late last year.

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The guns were bought to replace 25-year-old Ruger rifles at rural stations but at the time senior police said there would be policy considerations for the weapons being used by first-response police in siege situations.

The units cost police about $2200 each but sources told The Courier-Mail the stolen weapon could be sold for more on the black market if there was demand for it.

The weapon was not sent in a shipment of weapons but was a single package.

Specifications on the Nioa website state the gun weighs 3.18kg with a maximum effective range of 600m.

While the gun is semi-automatic, if it was ever able to be converted to full automatic its specifications state its fire rate capabilities between 700 and 950 rounds per minute.

Sources said police weapons were regularly sent via Australia Post without incident when officers relocated or replacement weapons were required.

However, a different freight company was involved in the recent weapon loss.

The Courier-Mail has been told an employee of a courier company was charged in relation to two handguns that went missing a number of years ago.

Regulations around the movement of firearms in Queensland state that the package should be a securely closed container and its shape should not suggest the presence of a firearm.

Marks, labels or names such as a gun shop that could indicate a weapon is inside are not permitted.

A police spokesman confirmed the rifle had been lost and an investigation had been launched.

Questions in relation to policy for transporting weapons were not answered, other than stating procedures adopted complied with legislative obligations under the Weapons Act.

"The QPS is aware of an incident where a weapon was allegedly forwarded by a supplier however the item did not arrive at its intended destination," a police statement said.

"The QPS did not incur any cost as the item was never received."