Sri Lanka bomber had studied in Australia

One of the suicide bombers involved in the Sri Lanka attacks studied in Australia, officials have confirmed.

"We believe one of the suicide bombers studied in the UK and maybe later on did his post-graduate (degree) in Australia before coming back to settle in Sri Lanka," Sri Lankan junior defence minister Ruwan Wijewardene told a media conference.

He confirmed Australian intelligence agencies were helping with the investigation, alongside Interpol and British security authorities.

It is understood Prime Minister Scott Morrison and Opposition Leader Bill Shorten will be briefed by security agencies on the development.

The death toll from the Easter Sunday attacks has been revised up to 359, with about 500 wounded.

Labor frontbencher Mark Butler says the revelation that one of the bombers had studied in Australia was a really "disturbing development".

"A very disturbing development in a really tragic story," he told ABC TV on Wednesday.

"All of us have been deeply touched by what happened on Easter Sunday."