The brother of two British Columbia men who died when their plane crashed into the sea off the B.C. coast three years ago, thinks he can explain why severed feet keep washing up on the shoreline.

In the last year alone, four shoes containing the remains of human feet have been found on the shorelines of islands located on B.C.'s Georgia Strait. The latest was discovered Thursday on Kirkland Island, in the Vancouver suburb of Richmond.

Kevin DeCock thinks the feet could belong to his brothers, Doug and Trevor DeCock, who both died in a February 2005 when their float plane crashed near Quadra Island.

Three other passengers also died in the crash.

Days later, the body of one the victims washed ashore on Quadra Island but it was not either of the DeCock brothers.

The families then paid for the plane wreckage to be pulled from the depths but there were no bodies inside.

Since the crash, Kevin DeCock has made it his singular focus to find his brothers.

"It's hard to stomach that they're laying there -- and they're there to be found," DeCock told CTV British Columbia on Thursday.

Last August, when the two feet washed ashore, DeCock said he began to think there could be a connection.

DeCock said he was dragging a hook from his search boat two weeks before the first two feet were found and he thinks he could "have stirred something up."

"The drift pattern shows that the current that day would start taking them... south, down to where the first foot was found," he said.

Police say none of the feet were forcibly removed from the bodies, and decomposition experts say limbs can break free if bodies are in the water long enough.

Two months ago, DeCock's father gave police a DNA sample to see if the feet can be connected to either of the brothers.

"They're going to the extent of taking DNA so there must be some interest in that department," said DeCock.

Sally Feast, sister of Arnie Feast, the float plane's pilot, collected DNA from an old toothbrush of Arnie's.

"The first (foot), with no answers, I thought about that right away," she said. "Second one even more so. Third one -- that was it -- then it was time to find out from the coroner -- maybe we should get some DNA on this."

Along with Feast, DeCock is now waiting for the results to address what he firmly believes -- that the mystery of the missing feet is connected to the disappearance of the missing crash victims.

With a report from CTV British Columbia's Shannon Paterson