As the search for a small plane that vanished in the Okanagan reaches its fifth day, rescue crews remain resolute – despite a possible connection between the pilot and a high-profile B.C. gang.

Air and land searches have been underway since the Victoria-bound Piper PA24 went missing on Tuesday, shortly after departing from the Penticton airport.

Now, questions have emerged about pilot Rama Tello and his circle of friends. An undated photograph found online shows Tello's roommate Matt Schrader posing with United Nations gang member Elliot "Taco" Castaneda, who was shot to death in Mexico in 2008.

Schrader declined to be interviewed on Sunday.

"It doesn't matter to us, the background of the individual or the stories we hear about the individuals," search master Capt. Scott Cursely said.

"Our job is to find an airplane with four individuals and bring closure one way or another to the families."

Some media outlets have also reported that the plane is connected to the B.C. drug trade.

Last week, Tello's friend Craig Wolf said he is disappointed with speculation about the plane. "It hurts the family, hurts the friends, children, husbands, wives. It's just improper in a time like this," he said.

The Canadian Forces is heading the search, with some civilian help – a $10,000 reward was offered by a private citizen to motivate people to join the search.

Authorities say they are still hopeful the passengers will be found, and they have received roughly 40 credible leads as to their whereabouts.

Extreme heat and smoke in the air caused difficult flying conditions on Tuesday, and hampered search efforts earlier in the week, but officials say cooler weather has helped for clearer conditions.

With a report from CTV British Columbia's Kent Molgat