OTTAWA - The Liberals stockpiled almost $700,000 in four B.C. ridings in the last election, dethroning two Conservative incumbents and one New Democrat, and losing to the NDP in the hotly contested riding of Vancouver East, election spending data show.

Those amounts, transfered back and forth between the candidates and a central party agency in British Columbia, helped in areas where the Liberals expected to be in tight races in a region all three parties considered a key campaign battleground.

But the transfer data also show how complicated it can be to follow the money in the world of election spending, where funds can move quickly between donors, candidates, local associations, and central parties.

Liberal Party officials explained that the four B.C. candidates are part of a service, now about a decade old in B.C., where the riding associations ship their money to a central party agency in the province that acts as auditor and administrator.

Returns filed with Elections Canada don't always make those transfers clear.

Those returns make it look like the national party - not associations - sent $225,415 to help Pam Goldsmith-Jones defeat Conservative John Weston in the B.C. riding of West Vancouver-Sunshine Coast-Sea to Sky Country, and $213,638 in Surrey-Newton where Sukh Dhaliwal defeated NDP MP Jinny Sims.

The party says that in fact the bulk of that money was raised by the B.C. riding associations but sent to the central service for safekeeping.

The service doesn't violate election spending rules; in fact, the Liberals are now looking to take the program nationwide and are asking party members to consider the idea as part of proposed changes to the party's constitution, said party spokesman Braeden Caley.

Excluding the B.C. candidates, the Liberals at the national level shipped almost $3 million in financial help to riding associations before, during and after the election to help Liberal candidates get elected on Oct. 19.

The spending was almost as much as the Conservatives and NDP combined shipped to their candidates from the central party.

In all and excluding the B.C. Liberal candidates, the four big parties that ran candidates across the country sent almost $6.4 million in cash, goods and services to help local candidates, based on a review by The Canadian Press of some 6,000 transactions filed before the end of March by about 1,500 candidates in the last election.

Some 200 candidates had yet to file returns by the end of the month, representing thousands more transactions.

Also missing from the data is how much the associations shipped up to the national parties themselves, each of whom could have spent up to $54.5 million during the 78-day campaign.

The Liberals - like the Conservatives and NDP - used detailed data tools to figure out where they should focus their efforts, although they kept the information to themselves.

The Liberals gained 15 seats in B.C., more than many Grits would have expected one month out from election day, said Mario Canseco, vice president of public affairs with research firm Insights West.

"It's not as if they have ever set the world on fire in B.C.," Canseco said. "It was almost like a pleasant surprise and I think this is why they decided to spend the money."

Canseco said fortunes changed for the Liberals heading into the last weeks of the campaign as many immigrant voters soured on the Tories over talk of a hotline for ethnic crimes. That gave the Liberals an opening to focus money into seats now open to them, Canseco said.

The figures also provide some insight into work the Liberals have before them to help their associations pad the local war chests for the next election in 2019, said Kathy Brock, a politics professor at Queen's University in Kingston, Ont.

A previous analysis by The Canadian Press found Conservative riding associations were flush with cash at the end of 2014, the most recent numbers available, with about $19 million available to help candidates across the country and the national campaign. That amount was more than the Liberals, NDP and Greens combined.

"This would raise the question of how strong are the Liberals on the ground. If the fortunes start to turn against them, do they have the strength to maintain their position and be competitive in the next election? Or are we seeing a fundamental weakness for them?" Brock said.

The spending figures show the Conservatives transferred more between associations than either the Liberals or NDP.