Operation Sunlag was an Australian military operation in Timor during World War Two. Its aim was to investigate what happened to Operation Lagarto.
On the 23rd April 45, Suncharlie operatives, connected to Sunlag, were deployed from HMAS River Snake, an Australian built Country Craft, some using Hoehn military folboats (collapsible canoes). Although this operation was intended to be for long term intelligence work, they returned to Riversnake on 26 April 45.
On 29 June 45, the Sunlag party parachuted in from a Liberator from No. 200 Flight RAAF to relieve Lagarto. Captain A.D. Stevenson and Sergeant R.G. Dawson, both of Z Special Unit, and Celestino dos Anjos, a Timorese guide, were parachuted into Timor two days ahead of a proposed supply drop to Operation Lagarto. They observed Sergeant Ellwood, who had been part of Lagarto, as being under guard. He had been missing for some time and was now obviously a captive. A rendezvous on 15–16 July 45, using Krait, was unsuccessful. Ellwood and others were finally rescued, together with the Brim party by HDML 1324 on 5 August 1945.
On the night of 29–30 June 1945, Stevenson's party landed safely in an area close to the signalled drop zone and made preparations to observe any Japanese intervention and discovered Operation Lagarto had been compromised. Due to problems with their radio set, they were unable to contact Australian. In the meantime, Operation Suncob had been undertaken and its men were captured and killed.
Dawson, Stevenson and Anjos had to survive pursuing Japanese for five weeks and were successfully rescued. However Dawson died of kidney failure on 10 August 1945 shortly after his return to Australia.