A friend told the Australian Kwan was very devoted to his family.
They described the situation as "really tragic".
WA Premier Mark McGowan said Mr Kwan spent his final moments alone because he was quarantined.
"It would have been awful, they couldn't go in and touch him or hold his hand, it would have been so tragically sad," Mr McGown said about Mr Kwan's family.
"You don't want to leave this world without someone holding your hand."
Western Australia's chief health officer Andrew Robertson Mr Kwan's wife was also in quarantine.
Robertson said the man's wife had a chance to talk to him before he died. His family spoke to him by phone or through glass on Saturday night.
"She had the opportunity to talk to him prior to his death, but she's understandably quite upset. And I obviously ask that people respect their privacy," Robertson said.
"He was identified very early on, when he was on the flight back from the Diamond Princess, he was put in isolation, he was transferred to us, and obviously placed in isolation on arrival.
"He's been managed in isolation ever since. There's no risk to the general community or to staff.
"He was in a negative pressure room and then in intensive care and they were very confident that the protection equipment they were using was more than adequate."
He had been taken from a Darwin quarantine camp with his wife, who is also infected, after being isolated in a quarantine camp there from Japan.
The couple were two of 164 Australians and six New Zealand passengers who were quarantined aboard the Diamond Princess with coronavirus then flown from Japan to Darwin.
Australians were placed in isolation at the Howards Springs camp, while Kiwis were flown to Auckland and placed in at a centre in Whangaparaoa.
Two other Kiwis and 10 Australians tested positive for coronavirus in mandatory screening before boarding the flight and were told they had to stay behind.
They were taken to hospital in Japan.
Kwan's wife Theresa is now in isolation at a Perth hospital.
She said in a statement that her husband died peacefully knowing his family loved him.
Just hours after Kwan's death, a sixth person was diagnosed with coronavirus in NSW.
A woman in her 50s is the latest to be diagnosed with the virus after recently returning to Australia from Iran.
She flew back to Sydney on February 23 on Qatar Airways Flight QR 908 and developed symptoms of the virus the following day.
She was tested for the coronavirus on February 29 after presenting to a hospital emergency department.
The cruise ship Diamond Princess at Yokohama Port for supplies, south of Tokyo. Photo / Hiroki Yamauchi, Kyodo News via AP
Because the woman's symptoms began within 24 hours of arriving in Sydney, people who were sitting close to her on her flight will be followed up and asked to self-isolate.
The latest case of the coronavirus in NSW is not linked to, and was not on the same flight, as the fifth confirmed case who has also returned from Iran but on a different day.
Victoria has also confirmed another case of coronavirus, with a woman in her 30s becoming the ninth person in the state to come down with the illness.
The state's Department of Health and Human Services confirmed on Sunday the woman landed in Melbourne from Iran.
The Victorian woman travelled from Tehran via Kuala Lumpur and Bali, arriving in Australia around 6am on Friday.
She started feeling unwell while travelling to Melbourne, and authorities are following-up with fellow plane travellers.
She was admitted to hospital on Saturday and put in isolation, then confirmed positive for the Covid-19 virus on Sunday.
Another person who was in contact with the woman will be tested for the virus and has been forced to self-isolate at home for 14 days.
An official in protective suits checks the temperature of the foreign passengers disembarked from the quarantined Diamond Princess cruise ship. AP Photo / Eugene Hoshiko
As coronavirus deaths in Iran spiral upwards, the man becomes Australia's second infected person returning from there to test positive for the virus.
Aged in his 40s, the man flew into Sydney from Iran on February 22 and developed symptoms two days later.
On Friday, he went to hospital where he was tested for Covid-19.
"He was advised to be isolated at home while waiting for the test result which was confirmed positive for Covid-19 late on 29 February," NSW chief health officer Kerry Chant said.
He has not displayed severe symptoms, but is being treated in Sydney Westmead Hospital.
The man was recorded as the second case in Australia to have come from Iran after a Gold Coast beautician tested positive for Covid-19 late on Friday.
The woman, 63, had returned from Iran on Monday and gave up to 40 customers facial treatments at the salon before she fell ill on Thursday.
Anyone who went to Hair Plus salon, in the Australia Fair shopping centre at Southport, Queensland last week is advised to get tested.
Workers disinfect subway trains against coronavirus in Tehran, Iran. Photo / Sajjad Safari, IIPA via AP
The woman is now in a stable condition and in isolation in the Gold Coast University Hospital.
A Sydney man who is being tested for the coronavirus could be the first person in Australia to contract the disease through person-to-person transmission.
The man in his 50s, understood to be a medical worker, is believed to have travelled to China months ago but has just recently started showing signs of the virus, the Daily Telegraph reported.
He is currently being cared for in a NSW hospital while he undergoes testing for the coronavirus.
"Additional specimens were collected overnight and are being tested today to confirm whether or not he has the infection," a NSW spokesperson said.
"He is currently being cared for in hospital. No more personal details relating to this patient will be released at this stage."
There are yet to be any confirmed cases of person-to-person transmission in Australia.
All four of NSW's previous coronavirus cases have since been discharged from hospital.
A sixth person, a man aged in his 50s, is currently being tested for Covid-19.
A total of 23 coronavirus infections have been recorded in Australia to date.
After activating a coronavirus emergency response plan for Australia on Thursday, Prime Minister Scott Morrison imposed an Iran travel ban which came into force today.
Foreign nationals coming from Iran will be forced to spend a fortnight in a third country before being allowed into Australia.
Australian citizens and permanent residents will need to isolate themselves for a fortnight after returning from Iran.
Iran has recorded 43 deaths from coronavirus, nine more since it had on Saturday, and has the highest Covid-19 mortality rate outside China.
Predictions are the death toll will continue to rise and the World Health Organisation has dispatched a medical team to Iran.
The Australian Government has a ban on foreign nationals who leave China from entering Australia for a duration of two weeks.
As of Sunday morning, more than 79,251 coronavirus cases had been recorded in China, followed by 3150 in South Korea, 1128 in Italy, 593 in Iran and 241 in Japan.
The world death toll is 2941, with 2727 of those in the Wuhan province Hubei, a total of 54 in other parts of China, 29 in Italy and 16 in South Korea.
