A bride-to-be wept in court as her fiance and his brother were denied bail after allegedly being caught with a "copious" amount of drugs, weapons and cash.

Brothers Jethro Todd, 29, and Johnas Todd, 36, were arrested when police raided their Uki NSW properties on Friday.

Police allege they found more than 300 marijuana plants, 2000 MDMA pills, $15,750 in cash and various weapons including a crossbow.

The case returned to Tweed Heads Local Court on Monday where the men were supported by family as they applied for bail.

Police prosecutor Sergeant Val Short told the court the brothers, who lived in separate homes on their parents' property, had been under police surveillance since June 2019.

Sergeant Short said police found a hydroponic set up of marijuana plants with an estimated street value of almost $1 million on Jethro's property.

She said the "sophisticated set up" was underneath Jethro's living room.

Sergeant Short said prosecution opposed both bail applications due to the risk of the brothers interfering with witnesses and evidence and it was still an ongoing investigation.

Jethro is charged with cultivation of a large commercial quantity of prohibited plant enhanced indoor means and knowingly dealing with proceeds of crime.

Darren Mahony, lawyer for Jethro and Johnas, told the court his clients' mother could offer $100,000 surety for each son to mitigate bail concerns.

Their mother wrote to the magistrate, "I want you to know that my sons have the support of both myself and their father".

"If Jethro and Johnas remain in custody we are concerned about the future of the business, noting that they have loans to pay off".

Mr Mahony said Jethro was due to marry his fiancee in a week and had spent a significant amount of money organising the wedding.

He said there was no evidence Jethro was supplying the marijuana, nor was their evidence of harvesting and rejected the claim his clients would interfere with witnesses or evidence.

Police allege they found 2000 MDMA pills in Johnas's kitchen, as well as marijuana plants, multiple weapons including rifles, hand guns, a crossbow and the materials to make a silencer.

Johnas was charged with seven offences including cultivate prohibited plant, supply prohibited drug large commercial quantity, possess unregistered firearms and manufacture a prohibited firearm without licence.

Mr Mahony argued his client's pregnant partner relied on Johnas for financial support which would cease if he was remanded in custody.

He said the brothers had committed to future projects with their earthworks business which their father also relied on for financial support.

Magistrate Geoff Dunlevy said the prosecution seemed to have a strong case against the brothers and he had to balance the facts against their submissions.

Mr Dunlevy said according to police facts there was allegedly a "copious quantity of drugs found".

The brothers remained stone faced as Mr Dunlevy refused their bail application.

Both cases will be back in court on May 11.

REVEALED: 500,000 pages of documents state wont let you see

Premium Content REVEALED: 500,000 pages of documents state wont let you see

Thousands spent trying to uncover secret government documents

VOTE NOW: Which's the Best Bakery in Gatton region

Premium Content VOTE NOW: Which's the Best Bakery in Gatton region

VOTE NOW: Which's the Best Bakery in Gatton, Lockyer, Bris Valley

Shooters killed cows and removed some of their meat: Cops

Premium Content Shooters killed cows and removed some of their meat: Cops

Police investigating shooting of cows and deer