Paris: There will be an unprecedented level of security at Anzac Day ceremonies across Europe this weekend, Foreign Minister Julie Bishop says.

She said security measures were "constantly" being reviewed after the arrest of a British teenager in connection with an alleged plan for an Anzac Day terror attack in Australia, one week before Australians across Europe gather to remember 100 years since the Gallipoli landings.

Messages found on 'media devices' linked to the 14-year-old boy from Blackburn led to Operation Rising in Australia, a major counter-terrorism operation involving the arrest of five teenagers in Melbourne, one of whom was charged with conspiracy to carry out an act of terrorism.

The BBC reported the British boy was first arrested on April 2, then detained again on Saturday after police searched an address in Blackburn and examined several electronic devices.

They allegedly found messages sent to a man in Australia.

"(The messages) were a concern to us," Detective Chief Superintendent Tony Mole, of the North West Counter Terrorism Unit told UK media. "We thought it indicated a potential credible terrorist attack in Australia. We immediately contacted the Australian authorities and we've been working with them since in relation to the material that we uncovered."

A team of UK officers have arrived in Australia to help with the investigation.

The British teenager is being held in police custody on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.

Mr Mole said police had not uncovered an imminent attack in the UK.

However, on the weekend British police were reviewing security operations ahead of the Anzac ceremonies, including services at the Cenotaph and Westminster Abbey in London that will be attended by descendants of Anzac veterans, the Queen, and Prince William (imminent royal baby permitting).

In Paris on Monday, Ms Bishop said there was an emerging strain of terrorism linked to IS in Iraq and Syria that was dangerous, global and unprecedented.

"I'm aware that terrorist attacks can take place at any place and any time," she said.

The countries hosting Anzac services including the UK, Belgium, France and Turkey were "very conscious" of the need to take appropriate steps to keep people safe, she said.

"I would think there will be an unprecedented level of security across the globe for events such as this."

"We are constantly reassured by governments that security arrangements are constantly being reviewed. Just as we do in Australia countries are doing that likewise overseas and those who are hosting Anzac ceremonies and similar ceremonies are taking steps to ensure that the security is appropriate.

"We will have representatives in London … and I'm assured that the security will be as appropriate as it can be, as it will be here in France and in Belgium where I'll be at the Menin Gate (in Ypres) on Anzac Day evening and morning."

Ms Bishop also defended a new intelligence-sharing deal with Iran, discussed during her visit there over the weekend, the first by an Australian minister in more than a decade.

"We need to get as much information as we can on the Australians who are fighting in Iraq and Syria," she said.

Independent MP and former Office of National Assessments analyst Andrew Wilkie called the intelligence-sharing plan "complete and utter madness".

"(Iran) will feed us bucketloads of crap which they will call intelligence, which … will simply be disinformation," he said, calling for the deal to be reconsidered.

"The regime in Iran can't be trusted and Australia is flirting with evil by establishing any sort of security relationship with it."

Ms Bishop said Australia didn't have a presence in Syria and very limited resources in Iraq, and needed to get information on the Australians fighting with terrorists in the region.

"That information will be useful for us should they come back to Australia. To be in al-Raqqa or to be in Mosul to fight with a terrorist organisation is an offence against the criminal laws of Australia and we would need the evidence to prove the case that these people were actually fighting for a terrorist organisation.

"I want Australia to be able to get that information from wherever we can."

Iran had offered information from its sources in Iraq and Syria and Ms Bishop accepted, she said.

"An informal information sharing agreement is absolutely appropriate."

Australia's intelligence agencies were well trained to assess the veracity and usefulness of information they received, she said.