The men were arrested on Thursday as part of ACT Policing's Operation Tribulation, a eight-month-long investigation into drug importation and trafficking in the territory.

During the past two and a half weeks, police raided a series of properties across the capital.

In a statement outside court, ACT Policing said during the raids officers had seized a firearm, more than $31,000 in cash, 1.3 kilograms of suspected dibutylone, 39 grams of suspected cocaine, and a small quantity of MDMA.

Three men arrested as part of the operation appeared in the ACT Magistrates Court on Friday, where they applied for bail.

Prosecutors opposed their release. The court heard that in relation to the drug trafficking offences, there was no presumption in favour of bail.

Cafe owner Peter Edward Poulakis, 28, of Wright, is charged with trafficking in a controlled drug other than cannabis and unauthorised possession of a firearm.

Builder Adam Ahmad Jabal, 27, of McKellar, and his brother Youssef Jabal, 32, who lives in Crace and owns a construction company, are charged with attempt traffic in controlled drug, attempt destroy or conceal evidence and pervert the course of justice.

Adam Jabal is also charged with attempt possess drug of dependence.

Chief Magistrate Lorraine Walker refused each man bail, saying there was a real risk they would interfere with the justice process.

Mr Poulakis, Ms Walker said, was alleged to have instructed one of his employees how to respond to police questions.

In relation to the brothers, Ms Walker said there was "strong evidence that these matters of interfering with the justice process are likely to be made out on the prosecution case."

She noted other names referred to in the police statement of facts.

"Clearly there is a wide network of people ... who could be influenced were the two defendants released from custody."

She remanded the men in custody.

The men were represented in court by defence solicitor Michael Kukulies-Smith.

The lawyer asked the chief magistrate to set down the three cases to return on Tuesday for a second attempt at bail.

The cases return February 19.

Police expect to lay further charges as the investigations continue.