Alleged Nazi war criminal Konrad Kalejs has arrived in his adopted country, Australia, amid renewed calls for his prosecution.

Mr Kalejs, an 86-year-old Australian citizen, landed in Melbourne on a Singapore Airlines flight.

He had travelled economy class and sat at the rear of the plane. Fellow passengers said he was hounded by reporters and photographers during the flight.

They said flight staff were forced to remove members of the press from the rear of the cabin.

Mr Kalejs cleared customs with fellow travellers, but was then escorted through a restricted area by security officials to a private car, avoiding the media and crowds of protesters, an airport spokeswoman said.

"I understand a friend of his picked him up. I've no idea where they've gone but there were no police or security officials in the car when it left the airport - just the two of them," she said.

Mr Kalejs is thought to have friends who will put him up but protesters have vowed to track him down.

Dozens of people gathered in the terminal to protest at what they said was the Australian government's failure to do more to investigate allegations against Mr Kalejs.

Mr Kalejs flew out of Britain voluntarily on Thursday after being warned that he faced deportation.

He is accused of murdering thousands of Jews in his native Latvia during World War II. Police in the UK decided there was not enough evidence to prosecute him.

'Enough evidence'

Bob Greenwood, former head of Australia's Special Investigation Unit (SIU) into war criminals, told Channel Nine television he thought there was enough evidence to start another full investigation.

"The first thing the government should do is to ascertain for humanitarian reasons the state of Mr Kalejs' health, whether he is intellectually and physically capable of defending himself against the allegations," he said.

"If the answer is yes, the Latvian authorities should be contacted - and the Americans and the British who have ongoing cases of this sort - a proper investigation, so the Australian public can be informed as to whether or not charges should be laid against this man."

Special treatment

Passengers said they were delayed from leaving the plane for about 10 minutes while Mr Kalejs was removed from the cabin behind a protective screen.

Earlier, during a transit stop in Singapore, police and airline officials smuggled Mr Kalejs off the Singapore Airlines flight from Heathrow in a sealed catering van.

He was then seen walking unaided onto the connecting flight to Australia.

Protesters at Melbourne said they were undeterred by airport officials' plan to usher Mr Kalejs away without passing through any publicly accessible areas.

"That's irrelevant," said one, Josh Gladwin. "We're here to prove to that he's not welcome here in Australia."

Denies allegations

Australia's justice minister, Amanda Vanstone, has said the file on Mr Kalejs remains open and she has promised to pursue new evidence against him if and when it is presented.

Mr Kalejs had been living in a retirement home in the UK, but left after the authorities launched proceedings to deport him for his alleged wartime atrocities.

He is alleged to have been an officer in a notorious Nazi death squad responsible for the murder of 30,000 people.

Mr Kalejs denies the allegations against him but was deported to Australia from the United States in 1994 and from Canada in 1997 because of his alleged war crimes.