(Reuters) -Democratic U.S. Senator Elizabeth Warren criticized Wells Fargo & Co for failing to protect its customers from fraud and scams on Zelle, a digital payments platform owned by seven of the biggest U.S. banks.

In a letter dated Oct. 6 but made public on Thursday, Warren told Wells CEO Charles Scharf the "alarming pattern" was made worse by the bank's refusal to make its Zelle scam and fraud data public.

In her letter, Warren, a prominent bank critic who sits on the Senate Banking Committee, claimed the bank's customers are reporting fraud and scams this year at a rate nearly 2.5 times higher than in 2019 and twice as high as those of other banks.

Zelle did not immediately respond to requests for comment.

Warren and other lawmakers have pressed large banks like Zelle to do more to protect consumers who suffer scams on the platform, and have demanded banks provide complete data on the level of Zelle fraud reported at each bank.

In a statement, a Wells Fargo spokeswoman disputed Warren's methodology, saying the bank's fraud claims related to Zelle are in line with the rest of the industry.

"As a member of Zelle, we've seen the number of transactions double in just three years, yet in 2022, 99.94% of our customer transactions occurred without incident. We don't believe the numbers in a recent report are done on a comparable basis, and therefore the analysis is misleading and inaccurate," said bank spokeswoman Amy Bonitatibus. She added that their data showed Zelle's fraud and scam rates were consistent with the industry and not twice as high compared to other banks.

The Zelle pressure comes as lawmakers like Warren have scrutinized the bank, which is working to address numerous woes from prior years, including a far-reaching fake accounts scandal and an unprecedented cap placed on its growth by the Federal Reserve.

(Reporting by Niket Nishant and Mehnaz Yasmin in Bengaluru and Pete Schroeder in Washington; Editing by Shounak Dasgupta, Anil D'Silva and Josie Kao)