Thousands of padlocks which were fixed to a city footbridge by lovers as a sign of their enduring commitment have been removed by Melbourne City Council contractors.

Around 20,000 locks were clipped to the railings along the bridge at Southbank, causing cables to sag.

Melbourne Lord Mayor Robert Doyle said the council intended to keep the bridge free of new locks in the future.

"In the future we'll keep the bridge clean of those locks - we'll do [a cull] from time to time," he said.

"[If you attach a lock tomorrow morning] I wouldn't go back in the afternoon, you'll get an unpleasant surprise."

Cr Doyle said the locks would be stored while the city decided their fate.

"We'll find some place, we'll put them in a giant box and keep them until we get a great idea about what to do," he said.

Couple walk by in time to save love lock

Craig Ploog and his fiancee, Emily Thompson, salvage their padlock from Southgate footbridge. ( ABC News: Mark Doman )

Craig Ploog said he and his fiancee, Emily Thompson, attached a lock to the bridge in 2013.

"It was a bit of a novelty," Mr Ploogs said.

"We'd heard about them being in Paris, the love locks, and it was an anniversary present a couple of years ago, when we'd just got engaged," he said.

"I just thought it'd be a nice night out, a nice way to maybe get a bit of a kiss at the end of the night."

He said he and Ms Thompson were walking in the area when they saw the locks being removed.

"I heard that all the locks were getting snipped off, and just saw all the workers and thought I'd go up and ask ... I never thought about getting it back to be honest, I just thought I'd ask because it's a nice little memento of the love lock bridge," he said.

A Melbourne City Council worker removes thousands of padlocks from Southgate footbridge. ( ABC News: Mark Doman )

Mr Doyle laughed off journalists' questions of whether the removal "was a good thing".

"Really? Do I think it's a good thing? Look I announced earlier this week that because of safety concerns, those wires are now getting very stretched, there are 20,000 locks on that bridge and all good things come to an end," he said.

"They've been up there for three years now; in Paris they've taken them off the Pont de l'Archeveche, in New York they give you about three minutes before they take them of, so we think three years is a pretty good run."

Ms Thompson said while it was sad to see the locks removed, she understood the council's reasons.

"Obviously it's not actually built to have the locks on here," she said.

"It was cool every time that we did actually walk over to have a look at it, and even for everyone else's, we put on ours a good couple of years ago and there wasn't nearly as many as now.

"So it's sad, but that's what has to happen."

Symbols of love, rusted and destroyed, in a dirty old bucket. ( ABC News: Mark Doman )

Sandridge Bridge may become a NYC High Line

Further along the Yarra River, Councillor Doyle floated the idea of redeveloping the Sandridge Bridge in the CBD by turning it into a massive garden.

Councillor Doyle said it could become something like New York's High Line gardens.

"Imagine if we gave it a treatment like the famous High Line in New York, which would make it a green bridge and something very pleasant to link the north and the south of our city," he said.

"I think that's one of the proposals for the Sandridge Bridge that would do a whole lot better than it's pretty sad state at the moment."

But he said he would have to convince the council and state government to fund the expensive proposal, as work would be required to support the extra weight it would need to carry.

"When there was some work being done on the redevelopment of Flinders Street Station there were suggestions that the bridge could be used as part of that redevelopment," he said.

"I must say I would much rather see it as a pedestrian link from the north to the south of the Yarra, and turning Queensbridge Square into our great open public space."