A long weekend police operation in southern New South Wales has taken nearly $2 million worth of illegal tobacco off the streets. 

More than 800 kilograms of loose tobacco leaf, as well as thousands of vapes and cigarettes, were seized in three separate incidents on the Hume Highway by highway patrol from the Riverina police district.

Riverina Police District Inspector Josh Broadfoot said the intercepts were the result of random road safety stops over the King's Birthday long weekend.

He said they added to the "significant figure" of contraband taken off Riverina highways so far this year.

"We're finding that we're getting a lot of these stops … three in one weekend is very significant," he said.

Commercial operation intercepted

Police conducting random breath testing stopped the vehicle of a 35-year-old Victorian woman on the Hume Highway at Gundagai on Sunday morning where the driver returned a negative result. 

A police search of the vehicle allegedly discovered 270,000 cigarettes and 825kg of loose tobacco leaf with an estimated street value of $1,125,000. 

Police also allege a large commercial tobacco leaf hydraulic bailing machine was located in the vehicle. 

The woman was arrested and taken to Cootamundra Police Station where she was charged with several offences linked to possession and illegal manufacture of tobacco. 

The woman was granted conditional bail to appear at Cootamundra Local Court on July 15.

Vapes seized

On Saturday afternoon, police stopped the vehicle of a 42-year-old man from Harris Park, Sydney.

Officers conducted a search of the vehicle where they allege 2,360 vapes with an estimated street value of $82,600 and 48 cartons of cigarettes worth about $14,400 were found along with $142,025 in cash. 

The man was arrested and taken to Gundagai police station where he was charged. 

He was granted conditional bail to appear at Gundagai local court on August 16. 

The third arrest was made Sunday afternoon when police stopped another vehicle on the Hume Highway at Coolac, north of Gundagai, after an alleged minor traffic offence. 

Cigarettes with an estimated value of $615,000 were located in the vehicle and both male occupants were arrested and taken to Cootamundra Police Station. 

The 32-year-old driver, a Victorian man, was charged and the passenger was released from custody following further police enquiries. 

The Victorian man was granted conditional bail to appear at Cootamundra Local Court on July 15. 

Inspector Broadfoot said officers trained in spotting the signs of vehicles transporting contraband were key to the intercepts and arrests.

"They highway [patrol officers] have done a great job in detecting these and disrupting these crime networks," he said.

"Our highway guys are disrupting a lot of this activity passing through the highways.