I got a first whiff of this news from RY after one of the guiding sessions at Raffles Museum. After seeing another similar news in yahoo yesterday, I was prompted to do some research on this topic since I am very free these days too.
Previously, only the Gila Monster and Bearded Lizard are the only species of lizards that possess venom. However, an article in Nature (2005) proved otherwise. Apparently, they found out that two additional lineages of lizards produce venom; the monitor lizards and iguanas. Interestingly, phylogenetic mapping of these toxins revealed that all these reptiles, including snakes, probably evolved from the same venomous ancestor.
An even more recent publication in PNAS a month back blasted the popular belief that Komodo Dragons (Varanus komodoensis) possess harmful toxic bacteria in their mouths that aid prey capture. In fact, none of these pathogens have been recorded in wild caught individuals. Instead, from a terminally ill Dragon in the Singapore Zoological Gardens, they discovered that they possess venom too! This toxin include anticoagulants and shock inducing proteins.
Malayan Water Monitor (Varanus salvator)
Even though our three species of monitors in Singapore; Clouded Monitor (Varanus bengalensis), the common Malayan Water Monitor (Varanus salvator) and the recently rediscovered Dumeril's monitor (Varanus dumerilii), have not been documented to have venom yet to the best of my knowledge; who knows they might do. But still, in contrast with the increasingly aggessive Komodo Dragons over at Indonesia, our monitors are still rather shy to humans and would not attack us unless provoked. Thus, there is no need for any alarm.