The accused kingpin of an international drug syndicate that smuggled 140 kilograms of methamphetamine into Australia inside diesel generators allegedly used the codewords "rice" and "beans" when arranging the illicit trade.

Nigerian-born Onyedika Hilary Anaeto, an Australian citizen, is accused of using the cover of his car wrecking business to participate in the West African organised crime ring.

He faced court on Tuesday after Australian Federal Police allegedly intercepted the drugs at Sydney Airport in 11 industrial diesel generators inside cargo containers.

Police have charged four people in Sydney and Melbourne over the alleged plot, two of them Nigerian nationals. It's understood more arrests might follow, and the investigation is ongoing.

Police secretly monitored the four men, recording their phone calls and movements, AFP documents tendered to the court show, including two trips Anaeto made to Sydney to meet his co-accused.

AFP federal agent Jason Hall told Melbourne Magistrates Court police had intercepted more than 7500 phone calls as part of the investigation and were in the process of painstakingly transcribing and translating those calls.

Senior Constable Hall alleged the men were talking in code in their phone calls, including one in which Anaeto was overheard saying some people would share the "rice" and some people would share the "beans".

In another taped conversation on June 1, according to AFP documents, Anaeto and a co-accused spoke about something being "tasted", and discussing whether "the person has the things that are needed to get them naked".

"They're not actually talking about specifics," Senior Constable Hall said. "Everything is coded."

He said Anaeto, who has family in Nigeria, was a flight risk and should not be granted bail.

"We believe that the applicant [for bail] is the main organiser of this drug coming into Australia," Senior Constable Hall said. "He was the go-between."

If Anaeto did not try to flee to Nigeria, he might "disappear" within Australia, Senior Constable Hall said.

"The African community in Australia is very large and intimate," he said. "He could disappear within Australia."

When Anaeto was arrested in Point Cook in Melbourne's south-west on June 4, he was carrying three mobile phones, the court heard.

The charges carry a maximum penalty of life imprisonment.

Defence lawyer Peter Morrissey SC said the claims Anaeto would disappear if he was granted bail were "just insulting, frankly".

The case against Anaeto, Mr Morrissey said, was "tendencious and not strong".

"It's not Mokbel, and it's not Barbaro," he said, referring to famous jailed drug kingpins.

"He presents of a person of good character, who is the breadwinner for his young family."

The court was told Anaeto had had his Australian passport seized, and had also willingly surrendered his Nigerian passport to prove he wasn't trying to flee the country.

Anaeto's wife was in court to support him, as were about 20 members of the Firm Foundation Ministries, of which Anaeto is a member.

Senior Pastor Chuks Iheakor gave evidence in support of Anaeto, but declined to swear an oath on the bible, instead swearing an affirmation.

Dr Iheakor, also an accountant who did Anaeto's tax returns, said his friend and client had a taxable income of about $51,000 in 2014-15.

He was a "well-received" member of the church, Dr Iheakor said.

Magistrate Elizabeth Lambden said Anaeto's legal team would have to prove there were exceptional circumstances that would warrant him being released from custody, given the nature of the allegations.

She was not convinced he met that test.

He was remanded in custody to reappear in court at a later date.