The bodies of the Martin Place siege victims will be laid to rest before Christmas.

Cafe manager Tori Johnson, 34, and barrister Katrina Dawson, 38, were killed at the end of a 16-hour siege staged by gunman Man Haron Monis, who also died.

The NSW Coroner announced that the victims' bodies had undergone autopsies and would be released to their families at 7pm on Thursday.

"The State Coroner's team has been working closely with the families over the past few days and they have already been informed the bodies will be ready for release this evening," a spokesman from the Attorney-General's Department said.

A funeral for Mr Johnson will be held next Tuesday in Sydney's eastern suburbs.

Fairfax Media understands that the autopsy on Monis' body will be carried out in the next few days.

Monis' autopsy is understood to be more complex than that for his victims due to the nature of his injuries.

His body will be released before Christmas.

While speculation mounted about precisely how Ms Dawson died, Fairfax Media understands investigating offers have reached no definitive conclusion about whose weapons the bullets were fired from.

A family friend of victim Tori Johnson said his family were "absolutely shattered" after learning the cafe manager had been shot at close range by Monis.

She said the family were too upset to speak but said Mr Johnson's partner, Thomas Zinn, was in the process of penning a tribute, which would be released on Friday morning.

"At the moment they are just shattered. Nobody is really talking to them at the moment."

Mr Johnson's aunt Lyn Whittaker has spoken about the moment she received the phone call, explaining her beloved nephew had been killed.

"The phone rang about 4.30 in the morning and it was Ken, my brother, and he said 'they've killed my beautiful boy' and he couldn't speak anymore," she told the ABC.

"The police officer came on and told my husband that Ken couldn't speak any more and this is what has happened.

She said her nephew was  "everything you could wish for in a son and grandson".

"A very, very, very brave boy, everything that people have said about Tori he was just the most caring, kind, gentle person," she said.

An Indian IT worker held hostage during the Martin Place siege says he is healing as each day passes, with the support of his wife.

He said his thoughts were with those who knew Katrina Dawson and Tori Johnson.

"I would also like to express my heartfelt condolences to the families of Katrina and Tori.

"As for me, I am fine and getting better every day," he said in a statement on Thursday.