Weather conditions made it impossible for members of the RCMP and B.C. Coroners Service to get to the remote crash site off Hesquiat Lake by air on Saturday.
Bill Yearwood, spokesman with the Transportation Safety Board, said the teams had to use boats to access the best shore nearest the crash site, and then make their way up logging roads and through heavily-wooded terrain.
"The RCMP and [B.C.] Coroners Service teams got in yesterday afternoon, and will be in there again this afternoon," Yearwood told CBC News Sunday morning.
"They have not been able to fly in, so getting there is slow. They go by boat and then by land, and that's taking up quite a bit of time," he said.
Yearwood said TSB investigators must wait until the RCMP and coroner's teams are finished before beginning their work at the site. The TSB investigation may have to wait until Monday afternoon to begin, he said.
"If they're able to complete their work today, that will give us an opportunity to go in tomorrow. All of this, of course, depends on the weather," he said.
The Air Nootka plane crashed Friday morning shortly after taking off from Hesquiat Lake, which is approximately 50 kilometres northwest of Tofino.
Four of those on board survived, although one is in critical condition.
Police say they believe the five passengers were hikers that Air Nootka was flying to the community of Gold River.
Air Nootka has released a statement calling the crash an "unfortunate incident" and identifying the plane as a de Havilland Beaver, but it says it won't comment further at this time.
The identities of the two victims are still being withheld.