Romeo “Romy” Castillo Jr, 34, was sent on the trip to the Indian Ocean island by employer DialAFlight as a reward for his “professionalism and enthusiasm”.
He was there for less than a week before the visit was cut short by the pandemic.
His brother Clive, 31, said Mr Castillo started showing symptoms of the virus after returning to the UK and began working from home in Pimlico.
He was admitted to Chelsea and Westminster Hospital where he lost his fight for life just three days later.
Clive said: “Romy was one of the sweetest and kindest souls you could ever meet,” he said. “He had a smile that really lit up a room.”
Mr Castillo’s parents, who live in the Philippines, were unable to attend his funeral on April 23 because of strict lockdown restrictions. The family have set up an online fundraising page to pay for a memorial next year. It has so far raised more than £6,000.
Clive said: “We can’t thank the NHS staff enough. They really looked after my brother in his final days. Lockdown restrictions have been far tougher in the Philippines and there was no way mum and dad could come over. The huge amount of support we have received since my brother died just shows how loved he was.”
He added: “I don’t want to tell anyone what to do, but I do think some people think this virus just won’t affect them. My brother was only 34 years old and it took him, I don’t want any other families to go through what mine have.”
A DialAFlight spokesman said Mr Castillo, who joined last year, was awarded the fact-finding trip to Mauritius in recognition of his work.
“He loved every minute of it and had the most amazing time. Romeo was highly thought of and much loved by his team and his clients.
“He loved his job and had a passion for travel and always worked hard to better himself.
“Everyone who worked with Romeo and who met him knew he was a genuinely lovely person. Romeo was a gentle, generous person and will be sorely missed.”