Sydney's Australian Reptile Park has put out a festive-period warning after reporting a record number of "massive" funnel-web spiders handed in to its keepers.

The park said the funnel-webs, the deadliest spiders in Australia, were mainly males and had leg spans of up to 10 centimetres, some of the biggest spiders the keepers have seen.

The venom of the male Sydney funnel-web is six-times more potent than that of the female.

Australian Reptile Park head of spiders, reptiles and venom Dan Rumsay described the creatures that were handed in as "massive".

"They're even scaring me and I have to work with them," he said.

Mr Rumsay said the park had been given 20 spiders over the past week.

Two funnel-web spiders that were handed in to Australian Reptile Park keepers. ( Supplied: Australian Reptile Park )

Victoria Museum senior curator of entomology Ken Walker said the sizes recorded were impressive.

"That's very large for these spiders without a doubt," he said.

Sorry, this audio has expired What to do if you're bitten by a funnel web

The recent wet weather in New South Wales was believed to be one of the reasons behind the influx of spiders, but it is also the height of the breeding season.

Dr Walker said that love, rather than the weather, was the key factor behind the sheer number of male spiders handed in.

"While there has been a lot of wild, wet weather in Sydney, the fact that mainly males have been handed in suggests to me that the weather really hasn't been a major factor," he said.

"This time of year is the typical time males mature, and once they mature they actually stop feeding and they just spend all of their time searching for females."

The spiders will be milked to create antivenom. ( Supplied: Australian Reptile Park )

The last death from a funnel-web spider in Australia was recorded in 1981, but Mr Rumsay said people needed to remain vigilant this summer.

"Last year a boy was bitten and I got to meet him. [He] was putting on his Harry Potter costume to go to a dress-up party and a spider was actually hiding in the clothes basket, so when he put the costume on it bit him," he said.

"Make sure you're checking all those things."

All the spiders handed into the reptile park will be put to good use: It's the only place in the country where the funnel-web is milked to create antivenom.