An ASIO officer may have inadvertently endangered a Melbourne man helping the intelligence organisation spy on the Islamic centre raided this week, after their secret conversations were revealed on social media.

Disclosure of their relationship is also believed to be the reason behind the decision to launch the series of anti-terror raids across the city on Wednesday, as the text messages, revealed to members of the group about two weeks ago, tipped off al-Furqan members that they were subject to a government investigation. More raids were conducted yesterday as Adnan Karabegovic, 24, appeared in the Melbourne Magistrates Court just after 4.30pm. He was charged with four offences of ''collecting documents connected with the preparation for the engagement of a person in, or assistance in, a terrorist act on September 12''.

The maximum penalty for the offence is 15 years' jail.

The court was told Karabegovic had lived in Australia since he was seven. He refused to stand for the magistrate, made no application for bail and no details were given in court of the alleged planned terrorist act. He was remanded to appear again for a committal mention on December 6.

The Melbourne man who helped ASIO spy on al-Furqan members, whom Fairfax will call X out of concerns for his safety, had been providing information to an ASIO officer identified only as ''Jay'' via text messages on his mobile phone.

Their relationship was exposed a fortnight ago when X was bashed and had his phone taken. Later, a group of men associated with the al-Furqan centre in Springvale South took photos of text messages on his phone and posted them on the centre's website, on Facebook and on other sites.

While it remains unclear exactly what happened when the phone was taken, a Facebook commenter wrote: ''the brother took the phone, after a sufficient evidence was presented [even this spy admitted to him that he is working for asio].''

The texting sparked outrage among the al-Furqan centre's members, with its leader, Harun Mehicevic, also known as Sheikh Harun and Abu Talha, giving an address recorded on the internet about the ''spying''.

Mr Mehicevic said the messages reveal ''a spynet of Muslims spying for ASIO, spying for kafir [unbelievers], on Muslims''.

Mr Mehicevic is believed to be overseas.

In all, 60 photos were posted on the web showing X's text conversation with Jay between May and August this year.

They reveal an avuncular, informal conversation peppered with text-speak at odds with the serious information being gathered. ''How important is that you know who jihad salafiyyah is? Cos I know lol,'' X messaged on July 22 regarding an online profile.

''Very important and don't tell me it's [name removed] lol,'' Jay responded. Soon after he wrote: ''Hey mate good work on who that name is, really helpful.''

Like other agencies that use human sources, ASIO would have strict guidelines on how to manage people that provide it with intelligence, in order to prevent their being discovered. The intelligence watchdog that oversees ASIO operations, Inspector General of Intelligence and Security Vivienne Thom, said she could not comment on whether her office was investigating the breach. ASIO also would not comment.

ASIO's Collection Division is responsible for running an array of human sources - people who provide information, often in return for money.

Jay is likely to be attached to the Victorian Joint Counter Terrorism Team, which includes members of Victoria Police, the federal police and ASIO. with Mark Russell