Investigators process a right foot that washed up on Kirkland Island, B.C. (CBC)

Another right foot wearing a sock and sneaker was discovered washed ashore near Vancouver, the RCMP confirmed Friday.

The foot is the fourth right foot wearing a sock and a running shoe to wash up in the area in less than a year.

The latest foot was discovered on uninhabited Kirkland Island in the Fraser River on Thursday.

The previous three washed up in the Gulf Islands between Vancouver and Vancouver Island. In August, two size 12 right feet were discovered on Gabriola and Jedediah islands, and a third foot was found in February on Valdes Island.

DNA tests were underway and experts in forensics, major crime and missing persons were all involved in the investigation, the RCMP said on Friday.

RCMP Cpl. Nycki Basra of Richmond said on Thursday that the case is one of the strangest she has heard of.

"Well, for us, it's our first time. In my 12 years of service, this is the first time I've seen it," she said about the most recently found foot.

Police are working to trace where the foot came from, Basra said. It could be the result of a suicide, an accident, or foul play.

Meanwhile, one man believes the feet may be remains of his two brothers and two other passengers who were in a plane that crashed in the waters off Quadra Island three years ago.

The bodies of the four men were never recovered, and Kevin Decock has been looking for the remains of his brothers since the crash in 2005.

Decock said he may have stirred up the ocean floor during a search last summer.

"I was out on the water conducting some surveys trying to bring up the engine from the plane crash, and I was dragging a hook. And two weeks after that the first foot showed up," Decock said.

His father provided authorities with a DNA sample two months ago, but Terry Smith, B.C.'s chief coroner, would only say that a full DNA profile exists for the first three of the four feet found, and officials have been unable to match the feet to any missing persons.

Smith cautioned against jumping to any conclusions, including that there might be foul play involved.

"This may very well be nothing more than the results of natural process of decomposition in water and the combined affects of predation by aquatic scavengers," Smith said.

It appears the first three feet were not severed, Smith said, but separated from the body through decomposition.