The Malaysian AIDS Council (MAC) president, Datuk Dr Raj Karim is saddened by the tragic loss of the front liners and advocates of HIV-AIDS who were on board the Malaysia Airlines (MAS) Flight MH17.

Many of the passengers on board MH17 en route from Amsterdam to Kuala Lumpur which crashed in Eastern Ukraine early Friday were AIDS researchers, activists, officials and scientists heading to the 20th International AIDS Conference in Melbourne, Australia.

"This is a real tragedy that should not have happened but we know that because of the war, innocent people are affected. We lost world renowned researchers, scientists, professionals and a lot of advocates of HIV-AIDS. They were the ones who gave voice to the whole HIV-AIDS scenario and they were the ones who made the call for access, treatments, care and support; access to drugs and they were non-discriminating, with no stigma whatsoever. It is truly a great loss for the world," said Raj.

Raj, who was recently re-elected to second term of MAC presidency, also said as a Malaysian, she felt somewhat responsible towards the whole tragedy due to the fact that it was a Malaysian aircraft. She hoped for the war and political turmoil in Ukraine, which has taken many innocent lives, to be stopped immediately.

"It was such a shocking tragedy and much unexpected. On behalf of MAC, our condolences and hearts go out to all family members and friends on board MH17. We share their grief and we highly appreciate their contributions thus far. Their legacy will be carried on by other fellow members and the rest of the AIDS community around the world," she said.

The ill-fated Flight MH17 was supposed to land in Kuala Lumpur early Friday after it took off from Schipol Airport in Amsterdam a little after noon.

A scheduled connection to Melbourne was due to arrive Friday evening.

Leading AIDS researcher and former International AIDS Society president, Joep Lange is thought to have been on the flight that went down in strife-torn Eastern Ukraine.

The 20th International AIDS Conference is a forum for activists to highlight grassroots and financing problems.

This year's conference was also expected to channel anger about laws in Africa that stigmatised homosexuality and in the former Soviet Union that punished intravenous drug users – a crackdown now extended to Russian-annexed Crimea.

Held every two years, this year's conference is due to start Sunday with 12,000 participants. Among world renowned activists expected to partake in the conference are legendary rock star Sir Bob Geldof and former US president Bill Clinton.

From Malaysia, several MAC members and professionals including Prof Dr Adeeba Kamarulzaman, representatives from University of Malaya's Centre of Excellence for Reseach in AIDS (CERiA) and the Health Ministry will also be attending the conference.