Telstra has blocked more than 13 million suspected scam calls in the past month, double the number it has blocked in previous months.

The telco said it is a two-fold increase on the 6.5 million suspected scam calls it was blocking just four months ago.

However, new upgrades to its platform have enabled Telstra to catch more suspicious calls through a more aggressive strategy.

Scamwatch says scam calls have cost Australians nearly $25 million already this year, and are on track to surpass last year’s $48.2 million lost to scam calls.

The use of call blocking is part of Telstra’s “Cleaner Pipes” initiative, which involves significantly upscaling its domain name system filtering, under which millions of malware communications are automatically blocked every week.