FILE PHOTO: An Apple company logo is seen behind tree branches outside an Apple store in Beijing, China December 14, 2018. REUTERS/Jason Lee/File Photo

WASHINGTON (Reuters) - Two key U.S. House of Representatives Democrats on Tuesday asked Apple Inc Chief Executive Tim Cook, to answer questions about a privacy flaw in Apple’s group video chat software after a teenager and his mother tried for days to warn the iPhone maker of the bug.

Apple said on Friday it had fixed the issue with FaceTime and said it planned to improve how it handles reports of software bugs.

House Energy and Commerce Chairman Frank Pallone and Representative Jan Schakowsky, who chairs a subcommittee overseeing consumer issues said in a letter they were “deeply troubled” over how long it took Apple to address the security flaw.

They want to know when Apple first learned of the issue, the extent to which the flaw may have compromised consumers’ privacy, and if “there are other undisclosed bugs that currently exist and have not been addressed.”

Apple did not immediately comment to Reuters.

“Your company and others must proactively ensure devices and applications protect consumer privacy, immediately act when a vulnerability is identified and address any harm caused when you fail to meet your obligations to consumers,” the Democrats wrote. “We do not believe Apple has been as transparent as this serious issue requires.”

The flaw in the software allowed users to hear the audio of a person they were calling before that person answered the call.

Apple turned off the FaceTime group chat feature last week as its engineers worked to fix the issue.

“We want to assure our customers that as soon as our engineering team became aware of the details necessary to reproduce the bug, they quickly disabled Group FaceTime and began work on the fix,” Apple said in a statement last week.